gears: Update to slightly more modern OpenGL
Instead of using glxgears, which still uses OpenGL 2.1 and the fixed pipeline, we use a slightly modified es2gears, OpenGL 3.2, and the programmable pipeline.
This commit is contained in:
Emmanuele Bassi
parent
209c5c37f3
commit
0019eb7bf9
798
tests/gtkgears.c
798
tests/gtkgears.c
@ -1,4 +1,4 @@
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/* The rendering code in here is taken from glxgears, which has the
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/* The rendering code in here is taken from es2gears, which has the
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* following copyright notice:
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*
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* Copyright (C) 1999-2001 Brian Paul All Rights Reserved.
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@ -19,24 +19,93 @@
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* BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
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* AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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*
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* Ported to GLES2.
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* Kristian Høgsberg <krh@bitplanet.net>
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* May 3, 2010
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*
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* Improve GLES2 port:
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* * Refactor gear drawing.
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* * Use correct normals for surfaces.
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* * Improve shader.
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* * Use perspective projection transformation.
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* * Add FPS count.
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* * Add comments.
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* Alexandros Frantzis <alexandros.frantzis@linaro.org>
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* Jul 13, 2010
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*/
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#define _GNU_SOURCE
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#include <math.h>
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#include <stdlib.h>
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#include <string.h>
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#include <epoxy/gl.h>
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#include "gtkgears.h"
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#define STRIPS_PER_TOOTH 7
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#define VERTICES_PER_TOOTH 34
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#define GEAR_VERTEX_STRIDE 6
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/**
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* Struct describing the vertices in triangle strip
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*/
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struct vertex_strip {
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/** The first vertex in the strip */
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GLint first;
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/** The number of consecutive vertices in the strip after the first */
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GLint count;
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};
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/* Each vertex consist of GEAR_VERTEX_STRIDE GLfloat attributes */
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typedef GLfloat GearVertex[GEAR_VERTEX_STRIDE];
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/**
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* Struct representing a gear.
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*/
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struct gear {
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/** The array of vertices comprising the gear */
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GearVertex *vertices;
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/** The number of vertices comprising the gear */
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int nvertices;
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/** The array of triangle strips comprising the gear */
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struct vertex_strip *strips;
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/** The number of triangle strips comprising the gear */
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int nstrips;
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/** The Vertex Buffer Object holding the vertices in the graphics card */
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GLuint vbo;
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};
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typedef struct {
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/* The view rotation [x, y, z] */
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GLfloat view_rot[GTK_GEARS_N_AXIS];
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GLint gear1, gear2, gear3;
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/* The gears */
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struct gear *gear1;
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struct gear *gear2;
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struct gear *gear3;
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/** The location of the shader uniforms */
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GLuint ModelViewProjectionMatrix_location;
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GLuint NormalMatrix_location;
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GLuint LightSourcePosition_location;
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GLuint MaterialColor_location;
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/* The current gear rotation angle */
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GLfloat angle;
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/* The projection matrix */
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GLfloat ProjectionMatrix[16];
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/* The direction of the directional light for the scene */
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GLfloat LightSourcePosition[4];
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gint64 first_frame_time;
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guint tick;
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GtkLabel *fps_label;
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} GtkGearsPrivate;
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G_DEFINE_TYPE_WITH_PRIVATE (GtkGears, gtk_gears, GTK_TYPE_GL_AREA);
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G_DEFINE_TYPE_WITH_PRIVATE (GtkGears, gtk_gears, GTK_TYPE_GL_AREA)
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static gboolean gtk_gears_render (GtkGLArea *area,
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GdkGLContext *context);
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@ -47,16 +116,14 @@ static gboolean gtk_gears_tick (GtkWidget *widget,
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GdkFrameClock *frame_clock,
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gpointer user_data);
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static void destroy_gear (struct gear *g);
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GtkWidget *
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gtk_gears_new (void)
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{
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GtkWidget *gears;
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gears = g_object_new (gtk_gears_get_type (),
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"has-depth-buffer", TRUE,
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NULL);
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return gears;
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return g_object_new (gtk_gears_get_type (),
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"has-depth-buffer", TRUE,
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NULL);
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}
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static void
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@ -68,6 +135,11 @@ gtk_gears_init (GtkGears *gears)
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priv->view_rot[GTK_GEARS_Y_AXIS] = 30.0;
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priv->view_rot[GTK_GEARS_Z_AXIS] = 20.0;
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priv->LightSourcePosition[0] = 5.0;
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priv->LightSourcePosition[1] = 5.0;
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priv->LightSourcePosition[2] = 10.0;
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priv->LightSourcePosition[3] = 1.0;
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priv->tick = gtk_widget_add_tick_callback (GTK_WIDGET (gears), gtk_gears_tick, gears, NULL);
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}
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@ -81,6 +153,10 @@ gtk_gears_finalize (GObject *obj)
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g_clear_object (&priv->fps_label);
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g_clear_pointer (&priv->gear1, destroy_gear);
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g_clear_pointer (&priv->gear2, destroy_gear);
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g_clear_pointer (&priv->gear3, destroy_gear);
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G_OBJECT_CLASS (gtk_gears_parent_class)->finalize (obj);
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}
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@ -94,190 +170,469 @@ gtk_gears_class_init (GtkGearsClass *klass)
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}
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/*
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* Fills a gear vertex.
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*
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* Draw a gear wheel. You'll probably want to call this function when
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* building a display list since we do a lot of trig here.
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* @param v the vertex to fill
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* @param x the x coordinate
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* @param y the y coordinate
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* @param z the z coortinate
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* @param n pointer to the normal table
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*
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* Input: inner_radius - radius of hole at center
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* outer_radius - radius at center of teeth
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* width - width of gear
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* teeth - number of teeth
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* tooth_depth - depth of tooth
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* @return the operation error code
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*/
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static GearVertex *
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vert (GearVertex *v,
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GLfloat x,
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GLfloat y,
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GLfloat z,
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GLfloat n[3])
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{
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v[0][0] = x;
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v[0][1] = y;
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v[0][2] = z;
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v[0][3] = n[0];
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v[0][4] = n[1];
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v[0][5] = n[2];
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return v + 1;
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}
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static void
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destroy_gear (struct gear *g)
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{
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g_clear_pointer (&g->strips, g_free);
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g_free (g);
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}
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/**
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* Create a gear wheel.
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*
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* @param inner_radius radius of hole at center
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* @param outer_radius radius at center of teeth
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* @param width width of gear
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* @param teeth number of teeth
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* @param tooth_depth depth of tooth
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*
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* @return pointer to the constructed struct gear
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*/
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static struct gear *
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create_gear (GLfloat inner_radius,
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GLfloat outer_radius,
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GLfloat width,
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GLint teeth,
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GLfloat tooth_depth)
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{
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GLfloat r0, r1, r2;
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GLfloat da;
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GearVertex *v;
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struct gear *gear;
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double s[5], c[5];
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GLfloat normal[3];
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int cur_strip = 0;
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int i;
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/* Allocate memory for the gear */
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gear = g_malloc (sizeof *gear);
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/* Calculate the radii used in the gear */
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r0 = inner_radius;
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r1 = outer_radius - tooth_depth / 2.0;
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r2 = outer_radius + tooth_depth / 2.0;
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da = 2.0 * M_PI / teeth / 4.0;
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/* Allocate memory for the triangle strip information */
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gear->nstrips = STRIPS_PER_TOOTH * teeth;
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gear->strips = g_malloc0_n (gear->nstrips, sizeof (*gear->strips));
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/* Allocate memory for the vertices */
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gear->vertices = g_malloc0_n (VERTICES_PER_TOOTH * teeth, sizeof(*gear->vertices));
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v = gear->vertices;
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for (i = 0; i < teeth; i++) {
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/* A set of macros for making the creation of the gears easier */
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#define GEAR_POINT(p, r, da) do { p.x = (r) * c[(da)]; p.y = (r) * s[(da)]; } while(0)
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#define SET_NORMAL(x, y, z) do { \
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normal[0] = (x); normal[1] = (y); normal[2] = (z); \
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} while(0)
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#define GEAR_VERT(v, point, sign) vert((v), p[(point)].x, p[(point)].y, (sign) * width * 0.5, normal)
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#define START_STRIP do { \
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gear->strips[cur_strip].first = v - gear->vertices; \
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} while(0);
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#define END_STRIP do { \
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int _tmp = (v - gear->vertices); \
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gear->strips[cur_strip].count = _tmp - gear->strips[cur_strip].first; \
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cur_strip++; \
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} while (0)
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#define QUAD_WITH_NORMAL(p1, p2) do { \
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SET_NORMAL((p[(p1)].y - p[(p2)].y), -(p[(p1)].x - p[(p2)].x), 0); \
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v = GEAR_VERT(v, (p1), -1); \
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v = GEAR_VERT(v, (p1), 1); \
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v = GEAR_VERT(v, (p2), -1); \
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v = GEAR_VERT(v, (p2), 1); \
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} while(0)
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struct point {
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GLfloat x;
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GLfloat y;
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};
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/* Create the 7 points (only x,y coords) used to draw a tooth */
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struct point p[7];
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/* Calculate needed sin/cos for varius angles */
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sincos(i * 2.0 * G_PI / teeth + da * 0, &s[0], &c[0]);
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sincos(i * 2.0 * M_PI / teeth + da * 1, &s[1], &c[1]);
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sincos(i * 2.0 * M_PI / teeth + da * 2, &s[2], &c[2]);
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sincos(i * 2.0 * M_PI / teeth + da * 3, &s[3], &c[3]);
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sincos(i * 2.0 * M_PI / teeth + da * 4, &s[4], &c[4]);
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GEAR_POINT(p[0], r2, 1);
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GEAR_POINT(p[1], r2, 2);
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GEAR_POINT(p[2], r1, 0);
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GEAR_POINT(p[3], r1, 3);
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GEAR_POINT(p[4], r0, 0);
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GEAR_POINT(p[5], r1, 4);
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GEAR_POINT(p[6], r0, 4);
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/* Front face */
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START_STRIP;
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SET_NORMAL(0, 0, 1.0);
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v = GEAR_VERT(v, 0, +1);
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v = GEAR_VERT(v, 1, +1);
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v = GEAR_VERT(v, 2, +1);
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v = GEAR_VERT(v, 3, +1);
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v = GEAR_VERT(v, 4, +1);
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v = GEAR_VERT(v, 5, +1);
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v = GEAR_VERT(v, 6, +1);
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END_STRIP;
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/* Inner face */
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START_STRIP;
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QUAD_WITH_NORMAL(4, 6);
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END_STRIP;
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/* Back face */
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START_STRIP;
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SET_NORMAL(0, 0, -1.0);
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v = GEAR_VERT(v, 6, -1);
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v = GEAR_VERT(v, 5, -1);
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v = GEAR_VERT(v, 4, -1);
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v = GEAR_VERT(v, 3, -1);
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v = GEAR_VERT(v, 2, -1);
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v = GEAR_VERT(v, 1, -1);
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v = GEAR_VERT(v, 0, -1);
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END_STRIP;
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/* Outer face */
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START_STRIP;
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QUAD_WITH_NORMAL(0, 2);
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END_STRIP;
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START_STRIP;
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QUAD_WITH_NORMAL(1, 0);
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END_STRIP;
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START_STRIP;
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QUAD_WITH_NORMAL(3, 1);
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END_STRIP;
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START_STRIP;
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QUAD_WITH_NORMAL(5, 3);
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END_STRIP;
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}
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gear->nvertices = (v - gear->vertices);
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/* Store the vertices in a vertex buffer object (VBO) */
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glGenBuffers (1, &gear->vbo);
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glBindBuffer (GL_ARRAY_BUFFER, gear->vbo);
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glBufferData (GL_ARRAY_BUFFER,
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gear->nvertices * sizeof(GearVertex),
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gear->vertices,
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GL_STATIC_DRAW);
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return gear;
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}
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/**
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* Multiplies two 4x4 matrices.
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*
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* The result is stored in matrix m.
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*
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* @param m the first matrix to multiply
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* @param n the second matrix to multiply
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*/
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static void
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gear(GLfloat inner_radius, GLfloat outer_radius, GLfloat width,
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GLint teeth, GLfloat tooth_depth)
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multiply (GLfloat *m, const GLfloat *n)
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{
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GLint i;
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GLfloat r0, r1, r2;
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GLfloat angle, da;
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GLfloat u, v, len;
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GLfloat tmp[16];
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const GLfloat *row, *column;
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div_t d;
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int i, j;
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r0 = inner_radius;
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r1 = outer_radius - tooth_depth / 2.0;
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r2 = outer_radius + tooth_depth / 2.0;
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da = 2.0 * G_PI / teeth / 4.0;
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glShadeModel(GL_FLAT);
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glNormal3f(0.0, 0.0, 1.0);
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/* draw front face */
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glBegin(GL_QUAD_STRIP);
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for (i = 0; i <= teeth; i++) {
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angle = i * 2.0 * G_PI / teeth;
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glVertex3f(r0 * cos(angle), r0 * sin(angle), width * 0.5);
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glVertex3f(r1 * cos(angle), r1 * sin(angle), width * 0.5);
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if (i < teeth) {
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glVertex3f(r0 * cos(angle), r0 * sin(angle), width * 0.5);
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glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da),
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width * 0.5);
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}
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for (i = 0; i < 16; i++) {
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tmp[i] = 0;
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d = div(i, 4);
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row = n + d.quot * 4;
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column = m + d.rem;
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for (j = 0; j < 4; j++)
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tmp[i] += row[j] * column[j * 4];
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}
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glEnd();
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memcpy(m, &tmp, sizeof tmp);
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}
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/* draw front sides of teeth */
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glBegin(GL_QUADS);
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da = 2.0 * G_PI / teeth / 4.0;
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for (i = 0; i < teeth; i++) {
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angle = i * 2.0 * G_PI / teeth;
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/**
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* Rotates a 4x4 matrix.
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*
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* @param[in,out] m the matrix to rotate
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* @param angle the angle to rotate
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* @param x the x component of the direction to rotate to
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* @param y the y component of the direction to rotate to
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* @param z the z component of the direction to rotate to
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*/
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static void
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rotate(GLfloat *m, GLfloat angle, GLfloat x, GLfloat y, GLfloat z)
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{
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double s, c;
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glVertex3f(r1 * cos(angle), r1 * sin(angle), width * 0.5);
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glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), width * 0.5);
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glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da),
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width * 0.5);
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glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da),
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width * 0.5);
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}
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glEnd();
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sincos(angle, &s, &c);
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GLfloat r[16] = {
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x * x * (1 - c) + c, y * x * (1 - c) + z * s, x * z * (1 - c) - y * s, 0,
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x * y * (1 - c) - z * s, y * y * (1 - c) + c, y * z * (1 - c) + x * s, 0,
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x * z * (1 - c) + y * s, y * z * (1 - c) - x * s, z * z * (1 - c) + c, 0,
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0, 0, 0, 1
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};
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glNormal3f(0.0, 0.0, -1.0);
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multiply(m, r);
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}
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/* draw back face */
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glBegin(GL_QUAD_STRIP);
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for (i = 0; i <= teeth; i++) {
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angle = i * 2.0 * G_PI / teeth;
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glVertex3f(r1 * cos(angle), r1 * sin(angle), -width * 0.5);
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glVertex3f(r0 * cos(angle), r0 * sin(angle), -width * 0.5);
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if (i < teeth) {
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glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da),
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-width * 0.5);
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glVertex3f(r0 * cos(angle), r0 * sin(angle), -width * 0.5);
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}
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}
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glEnd();
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/**
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* Translates a 4x4 matrix.
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*
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* @param[in,out] m the matrix to translate
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* @param x the x component of the direction to translate to
|
||||
* @param y the y component of the direction to translate to
|
||||
* @param z the z component of the direction to translate to
|
||||
*/
|
||||
static void
|
||||
translate(GLfloat *m, GLfloat x, GLfloat y, GLfloat z)
|
||||
{
|
||||
GLfloat t[16] = { 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, x, y, z, 1 };
|
||||
|
||||
/* draw back sides of teeth */
|
||||
glBegin(GL_QUADS);
|
||||
da = 2.0 * G_PI / teeth / 4.0;
|
||||
for (i = 0; i < teeth; i++) {
|
||||
angle = i * 2.0 * G_PI / teeth;
|
||||
multiply(m, t);
|
||||
}
|
||||
|
||||
glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da),
|
||||
-width * 0.5);
|
||||
glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da),
|
||||
-width * 0.5);
|
||||
glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), -width * 0.5);
|
||||
glVertex3f(r1 * cos(angle), r1 * sin(angle), -width * 0.5);
|
||||
}
|
||||
glEnd();
|
||||
/**
|
||||
* Creates an identity 4x4 matrix.
|
||||
*
|
||||
* @param m the matrix make an identity matrix
|
||||
*/
|
||||
static void
|
||||
identity(GLfloat *m)
|
||||
{
|
||||
GLfloat t[16] = {
|
||||
1.0, 0.0, 0.0, 0.0,
|
||||
0.0, 1.0, 0.0, 0.0,
|
||||
0.0, 0.0, 1.0, 0.0,
|
||||
0.0, 0.0, 0.0, 1.0,
|
||||
};
|
||||
|
||||
/* draw outward faces of teeth */
|
||||
glBegin(GL_QUAD_STRIP);
|
||||
for (i = 0; i < teeth; i++) {
|
||||
angle = i * 2.0 * G_PI / teeth;
|
||||
memcpy(m, t, sizeof(t));
|
||||
}
|
||||
|
||||
glVertex3f(r1 * cos(angle), r1 * sin(angle), width * 0.5);
|
||||
glVertex3f(r1 * cos(angle), r1 * sin(angle), -width * 0.5);
|
||||
u = r2 * cos(angle + da) - r1 * cos(angle);
|
||||
v = r2 * sin(angle + da) - r1 * sin(angle);
|
||||
len = sqrt(u * u + v * v);
|
||||
u /= len;
|
||||
v /= len;
|
||||
glNormal3f(v, -u, 0.0);
|
||||
glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), width * 0.5);
|
||||
glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), -width * 0.5);
|
||||
glNormal3f(cos(angle), sin(angle), 0.0);
|
||||
glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da),
|
||||
width * 0.5);
|
||||
glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da),
|
||||
-width * 0.5);
|
||||
u = r1 * cos(angle + 3 * da) - r2 * cos(angle + 2 * da);
|
||||
v = r1 * sin(angle + 3 * da) - r2 * sin(angle + 2 * da);
|
||||
glNormal3f(v, -u, 0.0);
|
||||
glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da),
|
||||
width * 0.5);
|
||||
glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da),
|
||||
-width * 0.5);
|
||||
glNormal3f(cos(angle), sin(angle), 0.0);
|
||||
}
|
||||
/**
|
||||
* Transposes a 4x4 matrix.
|
||||
*
|
||||
* @param m the matrix to transpose
|
||||
*/
|
||||
static void
|
||||
transpose(GLfloat *m)
|
||||
{
|
||||
GLfloat t[16] = {
|
||||
m[0], m[4], m[8], m[12],
|
||||
m[1], m[5], m[9], m[13],
|
||||
m[2], m[6], m[10], m[14],
|
||||
m[3], m[7], m[11], m[15]};
|
||||
|
||||
glVertex3f(r1 * cos(0), r1 * sin(0), width * 0.5);
|
||||
glVertex3f(r1 * cos(0), r1 * sin(0), -width * 0.5);
|
||||
memcpy(m, t, sizeof(t));
|
||||
}
|
||||
|
||||
glEnd();
|
||||
/**
|
||||
* Inverts a 4x4 matrix.
|
||||
*
|
||||
* This function can currently handle only pure translation-rotation matrices.
|
||||
* Read http://www.gamedev.net/community/forums/topic.asp?topic_id=425118
|
||||
* for an explanation.
|
||||
*/
|
||||
static void
|
||||
invert(GLfloat *m)
|
||||
{
|
||||
GLfloat t[16];
|
||||
identity(t);
|
||||
|
||||
glShadeModel(GL_SMOOTH);
|
||||
// Extract and invert the translation part 't'. The inverse of a
|
||||
// translation matrix can be calculated by negating the translation
|
||||
// coordinates.
|
||||
t[12] = -m[12]; t[13] = -m[13]; t[14] = -m[14];
|
||||
|
||||
/* draw inside radius cylinder */
|
||||
glBegin(GL_QUAD_STRIP);
|
||||
for (i = 0; i <= teeth; i++) {
|
||||
angle = i * 2.0 * G_PI / teeth;
|
||||
glNormal3f(-cos(angle), -sin(angle), 0.0);
|
||||
glVertex3f(r0 * cos(angle), r0 * sin(angle), -width * 0.5);
|
||||
glVertex3f(r0 * cos(angle), r0 * sin(angle), width * 0.5);
|
||||
}
|
||||
glEnd();
|
||||
// Invert the rotation part 'r'. The inverse of a rotation matrix is
|
||||
// equal to its transpose.
|
||||
m[12] = m[13] = m[14] = 0;
|
||||
transpose(m);
|
||||
|
||||
// inv(m) = inv(r) * inv(t)
|
||||
multiply(m, t);
|
||||
}
|
||||
|
||||
/**
|
||||
* Calculate a perspective projection transformation.
|
||||
*
|
||||
* @param m the matrix to save the transformation in
|
||||
* @param fovy the field of view in the y direction
|
||||
* @param aspect the view aspect ratio
|
||||
* @param zNear the near clipping plane
|
||||
* @param zFar the far clipping plane
|
||||
*/
|
||||
void perspective(GLfloat *m, GLfloat fovy, GLfloat aspect, GLfloat zNear, GLfloat zFar)
|
||||
{
|
||||
GLfloat tmp[16];
|
||||
identity(tmp);
|
||||
|
||||
double sine, cosine, cotangent, deltaZ;
|
||||
GLfloat radians = fovy / 2 * M_PI / 180;
|
||||
|
||||
deltaZ = zFar - zNear;
|
||||
sincos(radians, &sine, &cosine);
|
||||
|
||||
if ((deltaZ == 0) || (sine == 0) || (aspect == 0))
|
||||
return;
|
||||
|
||||
cotangent = cosine / sine;
|
||||
|
||||
tmp[0] = cotangent / aspect;
|
||||
tmp[5] = cotangent;
|
||||
tmp[10] = -(zFar + zNear) / deltaZ;
|
||||
tmp[11] = -1;
|
||||
tmp[14] = -2 * zNear * zFar / deltaZ;
|
||||
tmp[15] = 0;
|
||||
|
||||
memcpy(m, tmp, sizeof(tmp));
|
||||
}
|
||||
|
||||
/**
|
||||
* Draws a gear.
|
||||
*
|
||||
* @param gear the gear to draw
|
||||
* @param transform the current transformation matrix
|
||||
* @param x the x position to draw the gear at
|
||||
* @param y the y position to draw the gear at
|
||||
* @param angle the rotation angle of the gear
|
||||
* @param color the color of the gear
|
||||
*/
|
||||
static void
|
||||
draw_gear(GtkGears *self,
|
||||
struct gear *gear,
|
||||
GLfloat *transform,
|
||||
GLfloat x,
|
||||
GLfloat y,
|
||||
GLfloat angle,
|
||||
const GLfloat color[4])
|
||||
{
|
||||
GtkGearsPrivate *priv = gtk_gears_get_instance_private (self);
|
||||
GLfloat model_view[16];
|
||||
GLfloat normal_matrix[16];
|
||||
GLfloat model_view_projection[16];
|
||||
int n;
|
||||
|
||||
/* Translate and rotate the gear */
|
||||
memcpy(model_view, transform, sizeof (model_view));
|
||||
translate(model_view, x, y, 0);
|
||||
rotate(model_view, 2 * G_PI * angle / 360.0, 0, 0, 1);
|
||||
|
||||
/* Create and set the ModelViewProjectionMatrix */
|
||||
memcpy(model_view_projection, priv->ProjectionMatrix, sizeof(model_view_projection));
|
||||
multiply(model_view_projection, model_view);
|
||||
|
||||
glUniformMatrix4fv(priv->ModelViewProjectionMatrix_location, 1, GL_FALSE,
|
||||
model_view_projection);
|
||||
|
||||
/*
|
||||
* Create and set the NormalMatrix. It's the inverse transpose of the
|
||||
* ModelView matrix.
|
||||
*/
|
||||
memcpy(normal_matrix, model_view, sizeof (normal_matrix));
|
||||
invert(normal_matrix);
|
||||
transpose(normal_matrix);
|
||||
glUniformMatrix4fv(priv->NormalMatrix_location, 1, GL_FALSE, normal_matrix);
|
||||
|
||||
/* Set the gear color */
|
||||
glUniform4fv(priv->MaterialColor_location, 1, color);
|
||||
|
||||
/* Set the vertex buffer object to use */
|
||||
glBindBuffer(GL_ARRAY_BUFFER, gear->vbo);
|
||||
|
||||
/* Set up the position of the attributes in the vertex buffer object */
|
||||
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(GLfloat), NULL);
|
||||
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(GLfloat), (GLfloat *) 0 + 3);
|
||||
|
||||
/* Enable the attributes */
|
||||
glEnableVertexAttribArray(0);
|
||||
glEnableVertexAttribArray(1);
|
||||
|
||||
/* Draw the triangle strips that comprise the gear */
|
||||
for (n = 0; n < gear->nstrips; n++) {
|
||||
glDrawArrays(GL_TRIANGLE_STRIP, gear->strips[n].first, gear->strips[n].count);
|
||||
}
|
||||
|
||||
/* Disable the attributes */
|
||||
glDisableVertexAttribArray(1);
|
||||
glDisableVertexAttribArray(0);
|
||||
}
|
||||
|
||||
/* new window size or exposure */
|
||||
static void
|
||||
reshape(int width, int height)
|
||||
reshape(GtkGears *gears, int width, int height)
|
||||
{
|
||||
GLfloat h = (GLfloat) height / (GLfloat) width;
|
||||
GtkGearsPrivate *priv = gtk_gears_get_instance_private (gears);
|
||||
|
||||
glMatrixMode(GL_PROJECTION);
|
||||
glLoadIdentity();
|
||||
glFrustum(-1.0, 1.0, -h, h, 5.0, 60.0);
|
||||
/* Update the projection matrix */
|
||||
perspective (priv->ProjectionMatrix, 60.0, width / (float)height, 1.0, 1024.0);
|
||||
|
||||
glMatrixMode(GL_MODELVIEW);
|
||||
glLoadIdentity();
|
||||
glTranslatef(0.0, 0.0, -40.0);
|
||||
/* Set the viewport */
|
||||
glViewport (0, 0, (GLint) width, (GLint) height);
|
||||
}
|
||||
|
||||
static gboolean
|
||||
gtk_gears_render (GtkGLArea *area,
|
||||
GdkGLContext *context)
|
||||
{
|
||||
GtkGearsPrivate *priv = gtk_gears_get_instance_private (GTK_GEARS (area));
|
||||
static const GLfloat red[4] = { 0.8, 0.1, 0.0, 1.0 };
|
||||
static const GLfloat green[4] = { 0.0, 0.8, 0.2, 1.0 };
|
||||
static const GLfloat blue[4] = { 0.2, 0.2, 1.0, 1.0 };
|
||||
|
||||
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
|
||||
GtkGears *self = GTK_GEARS (area);
|
||||
GtkGearsPrivate *priv = gtk_gears_get_instance_private (self);
|
||||
GLfloat transform[16];
|
||||
|
||||
glPushMatrix();
|
||||
glRotatef(priv->view_rot[GTK_GEARS_X_AXIS], 1.0, 0.0, 0.0);
|
||||
glRotatef(priv->view_rot[GTK_GEARS_Y_AXIS], 0.0, 1.0, 0.0);
|
||||
glRotatef(priv->view_rot[GTK_GEARS_Z_AXIS], 0.0, 0.0, 1.0);
|
||||
identity (transform);
|
||||
|
||||
glPushMatrix();
|
||||
glTranslatef(-3.0, -2.0, 0.0);
|
||||
glRotatef(priv->angle, 0.0, 0.0, 1.0);
|
||||
glCallList(priv->gear1);
|
||||
glPopMatrix();
|
||||
glClearColor (0.0, 0.0, 0.0, 0.0);
|
||||
glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
|
||||
|
||||
glPushMatrix();
|
||||
glTranslatef(3.1, -2.0, 0.0);
|
||||
glRotatef(-2.0 * priv->angle - 9.0, 0.0, 0.0, 1.0);
|
||||
glCallList(priv->gear2);
|
||||
glPopMatrix();
|
||||
/* Translate and rotate the view */
|
||||
translate (transform, 0, 0, -20);
|
||||
rotate (transform, 2 * G_PI * priv->view_rot[0] / 360.0, 1, 0, 0);
|
||||
rotate (transform, 2 * G_PI * priv->view_rot[1] / 360.0, 0, 1, 0);
|
||||
rotate (transform, 2 * G_PI * priv->view_rot[2] / 360.0, 0, 0, 1);
|
||||
|
||||
glPushMatrix();
|
||||
glTranslatef(-3.1, 4.2, 0.0);
|
||||
glRotatef(-2.0 * priv->angle - 25.0, 0.0, 0.0, 1.0);
|
||||
glCallList(priv->gear3);
|
||||
glPopMatrix();
|
||||
|
||||
glPopMatrix();
|
||||
/* Draw the gears */
|
||||
draw_gear (self, priv->gear1, transform, -3.0, -2.0, priv->angle, red);
|
||||
draw_gear (self, priv->gear2, transform, 3.1, -2.0, -2 * priv->angle - 9.0, green);
|
||||
draw_gear (self, priv->gear3, transform, -3.1, 4.2, -2 * priv->angle - 25.0, blue);
|
||||
|
||||
return TRUE;
|
||||
}
|
||||
@ -293,55 +648,114 @@ gtk_gears_size_allocate (GtkWidget *widget,
|
||||
if (gtk_widget_get_realized (widget))
|
||||
{
|
||||
gtk_gl_area_make_current (glarea);
|
||||
reshape (allocation->width, allocation->height);
|
||||
reshape ((GtkGears *) glarea, allocation->width, allocation->height);
|
||||
}
|
||||
}
|
||||
|
||||
static const char vertex_shader[] =
|
||||
"#version 150\n"
|
||||
"\n"
|
||||
"in vec3 position;\n"
|
||||
"in vec3 normal;\n"
|
||||
"\n"
|
||||
"uniform mat4 ModelViewProjectionMatrix;\n"
|
||||
"uniform mat4 NormalMatrix;\n"
|
||||
"uniform vec4 LightSourcePosition;\n"
|
||||
"uniform vec4 MaterialColor;\n"
|
||||
"\n"
|
||||
"smooth out vec4 Color;\n"
|
||||
"\n"
|
||||
"void main(void)\n"
|
||||
"{\n"
|
||||
" // Transform the normal to eye coordinates\n"
|
||||
" vec3 N = normalize(vec3(NormalMatrix * vec4(normal, 1.0)));\n"
|
||||
"\n"
|
||||
" // The LightSourcePosition is actually its direction for directional light\n"
|
||||
" vec3 L = normalize(LightSourcePosition.xyz);\n"
|
||||
"\n"
|
||||
" // Multiply the diffuse value by the vertex color (which is fixed in this case)\n"
|
||||
" // to get the actual color that we will use to draw this vertex with\n"
|
||||
" float diffuse = max(dot(N, L), 0.0);\n"
|
||||
" Color = diffuse * MaterialColor;\n"
|
||||
"\n"
|
||||
" // Transform the position to clip coordinates\n"
|
||||
" gl_Position = ModelViewProjectionMatrix * vec4(position, 1.0);\n"
|
||||
"}";
|
||||
|
||||
static const char fragment_shader[] =
|
||||
"#version 150\n"
|
||||
"\n"
|
||||
"smooth in vec4 Color;\n"
|
||||
"\n"
|
||||
"void main(void)\n"
|
||||
"{\n"
|
||||
" gl_FragColor = Color;\n"
|
||||
"}";
|
||||
|
||||
static void
|
||||
gtk_gears_realize (GtkWidget *widget)
|
||||
{
|
||||
GtkGLArea *glarea = GTK_GL_AREA (widget);
|
||||
GtkGears *gears = GTK_GEARS(widget);
|
||||
GtkGears *gears = GTK_GEARS (widget);
|
||||
GtkGearsPrivate *priv = gtk_gears_get_instance_private (gears);
|
||||
GtkAllocation allocation;
|
||||
static GLfloat pos[4] = { 5.0, 5.0, 10.0, 0.0 };
|
||||
static GLfloat red[4] = { 0.8, 0.1, 0.0, 1.0 };
|
||||
static GLfloat green[4] = { 0.0, 0.8, 0.2, 1.0 };
|
||||
static GLfloat blue[4] = { 0.2, 0.2, 1.0, 1.0 };
|
||||
GLuint vao, v, f, program;
|
||||
const char *p;
|
||||
char msg[512];
|
||||
|
||||
GTK_WIDGET_CLASS (gtk_gears_parent_class)->realize (widget);
|
||||
|
||||
gtk_gl_area_make_current (glarea);
|
||||
|
||||
glLightfv(GL_LIGHT0, GL_POSITION, pos);
|
||||
glEnable(GL_CULL_FACE);
|
||||
glEnable(GL_LIGHTING);
|
||||
glEnable(GL_LIGHT0);
|
||||
glEnable(GL_DEPTH_TEST);
|
||||
glEnable (GL_CULL_FACE);
|
||||
glEnable (GL_DEPTH_TEST);
|
||||
|
||||
/* Create the VAO */
|
||||
glGenVertexArrays (1, &vao);
|
||||
glBindVertexArray (vao);
|
||||
|
||||
/* Compile the vertex shader */
|
||||
p = vertex_shader;
|
||||
v = glCreateShader(GL_VERTEX_SHADER);
|
||||
glShaderSource(v, 1, &p, NULL);
|
||||
glCompileShader(v);
|
||||
glGetShaderInfoLog(v, sizeof msg, NULL, msg);
|
||||
g_print ("vertex shader info: %s\n", msg);
|
||||
|
||||
/* Compile the fragment shader */
|
||||
p = fragment_shader;
|
||||
f = glCreateShader(GL_FRAGMENT_SHADER);
|
||||
glShaderSource(f, 1, &p, NULL);
|
||||
glCompileShader(f);
|
||||
glGetShaderInfoLog(f, sizeof msg, NULL, msg);
|
||||
g_print ("fragment shader info: %s\n", msg);
|
||||
|
||||
/* Create and link the shader program */
|
||||
program = glCreateProgram();
|
||||
glAttachShader(program, v);
|
||||
glAttachShader(program, f);
|
||||
glBindAttribLocation(program, 0, "position");
|
||||
glBindAttribLocation(program, 1, "normal");
|
||||
|
||||
glLinkProgram(program);
|
||||
glGetProgramInfoLog(program, sizeof msg, NULL, msg);
|
||||
g_print ("program info: %s\n", msg);
|
||||
|
||||
/* Enable the shaders */
|
||||
glUseProgram(program);
|
||||
|
||||
/* Get the locations of the uniforms so we can access them */
|
||||
priv->ModelViewProjectionMatrix_location = glGetUniformLocation(program, "ModelViewProjectionMatrix");
|
||||
priv->NormalMatrix_location = glGetUniformLocation(program, "NormalMatrix");
|
||||
priv->LightSourcePosition_location = glGetUniformLocation(program, "LightSourcePosition");
|
||||
priv->MaterialColor_location = glGetUniformLocation(program, "MaterialColor");
|
||||
|
||||
/* Set the LightSourcePosition uniform which is constant throught the program */
|
||||
glUniform4fv(priv->LightSourcePosition_location, 1, priv->LightSourcePosition);
|
||||
|
||||
/* make the gears */
|
||||
priv->gear1 = glGenLists(1);
|
||||
glNewList(priv->gear1, GL_COMPILE);
|
||||
glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, red);
|
||||
gear(1.0, 4.0, 1.0, 20, 0.7);
|
||||
glEndList();
|
||||
|
||||
priv->gear2 = glGenLists(1);
|
||||
glNewList(priv->gear2, GL_COMPILE);
|
||||
glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, green);
|
||||
gear(0.5, 2.0, 2.0, 10, 0.7);
|
||||
glEndList();
|
||||
|
||||
priv->gear3 = glGenLists(1);
|
||||
glNewList(priv->gear3, GL_COMPILE);
|
||||
glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, blue);
|
||||
gear(1.3, 2.0, 0.5, 10, 0.7);
|
||||
glEndList();
|
||||
|
||||
glEnable(GL_NORMALIZE);
|
||||
|
||||
gtk_widget_get_allocation (widget, &allocation);
|
||||
reshape (allocation.width, allocation.height);
|
||||
priv->gear1 = create_gear(1.0, 4.0, 1.0, 20, 0.7);
|
||||
priv->gear2 = create_gear(0.5, 2.0, 2.0, 10, 0.7);
|
||||
priv->gear3 = create_gear(1.3, 2.0, 0.5, 10, 0.7);
|
||||
}
|
||||
|
||||
static gboolean
|
||||
|
||||
Loading…
Reference in New Issue
Block a user