[gtk+] gtk-demo: Add gears to the bowl
- From: Matthias Clasen <matthiasc src gnome org>
- To: commits-list gnome org
- Cc:
- Subject: [gtk+] gtk-demo: Add gears to the bowl
- Date: Wed, 17 Jan 2018 19:40:22 +0000 (UTC)
commit b6d85b9e31917a6573b1f833b3d6cf7129337960
Author: Matthias Clasen <mclasen redhat com>
Date: Wed Jan 17 14:39:46 2018 -0500
gtk-demo: Add gears to the bowl
Just for fun.
demos/gtk-demo/gtkgears.c | 960 +++++++++++++++++++++++++++++++++++++++++++
demos/gtk-demo/gtkgears.h | 48 +++
demos/gtk-demo/meson.build | 4 +-
demos/gtk-demo/widgetbowl.c | 12 +
4 files changed, 1023 insertions(+), 1 deletions(-)
---
diff --git a/demos/gtk-demo/gtkgears.c b/demos/gtk-demo/gtkgears.c
new file mode 100644
index 0000000..32a24da
--- /dev/null
+++ b/demos/gtk-demo/gtkgears.c
@@ -0,0 +1,960 @@
+/* The rendering code in here is taken from es2gears, which has the
+ * following copyright notice:
+ *
+ * Copyright (C) 1999-2001 Brian Paul All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * Ported to GLES2.
+ * Kristian Høgsberg <krh bitplanet net>
+ * May 3, 2010
+ *
+ * Improve GLES2 port:
+ * * Refactor gear drawing.
+ * * Use correct normals for surfaces.
+ * * Improve shader.
+ * * Use perspective projection transformation.
+ * * Add FPS count.
+ * * Add comments.
+ * Alexandros Frantzis <alexandros frantzis linaro org>
+ * Jul 13, 2010
+ */
+
+#include "config.h"
+
+#include <math.h>
+#include <stdlib.h>
+#include <string.h>
+#include <epoxy/gl.h>
+
+#include "gtkgears.h"
+
+#define STRIPS_PER_TOOTH 7
+#define VERTICES_PER_TOOTH 34
+#define GEAR_VERTEX_STRIDE 6
+
+#ifndef HAVE_SINCOS
+static void
+sincos (double x, double *_sin, double *_cos)
+{
+ *_sin = sin (x);
+ *_cos = cos (x);
+}
+#endif
+
+/**
+ * Struct describing the vertices in triangle strip
+ */
+struct vertex_strip {
+ /** The first vertex in the strip */
+ GLint first;
+ /** The number of consecutive vertices in the strip after the first */
+ GLint count;
+};
+
+/* Each vertex consist of GEAR_VERTEX_STRIDE GLfloat attributes */
+typedef GLfloat GearVertex[GEAR_VERTEX_STRIDE];
+
+/**
+ * Struct representing a gear.
+ */
+struct gear {
+ /** The array of vertices comprising the gear */
+ GearVertex *vertices;
+ /** The number of vertices comprising the gear */
+ int nvertices;
+ /** The array of triangle strips comprising the gear */
+ struct vertex_strip *strips;
+ /** The number of triangle strips comprising the gear */
+ int nstrips;
+};
+
+typedef struct {
+ /* The view rotation [x, y, z] */
+ GLfloat view_rot[GTK_GEARS_N_AXIS];
+
+ /* The Vertex Array Object */
+ GLuint vao;
+
+ /* The shader program */
+ GLuint program;
+
+ /* The gears */
+ struct gear *gear1;
+ struct gear *gear2;
+ struct gear *gear3;
+
+ /** The Vertex Buffer Object holding the vertices in the graphics card */
+ GLuint gear_vbo[3];
+
+ /** The location of the shader uniforms */
+ GLuint ModelViewProjectionMatrix_location;
+ GLuint NormalMatrix_location;
+ GLuint LightSourcePosition_location;
+ GLuint MaterialColor_location;
+
+ /* The current gear rotation angle */
+ GLfloat angle;
+
+ /* The projection matrix */
+ GLfloat ProjectionMatrix[16];
+
+ /* The direction of the directional light for the scene */
+ GLfloat LightSourcePosition[4];
+
+ gint64 first_frame_time;
+ guint tick;
+ GtkLabel *fps_label;
+} GtkGearsPrivate;
+
+G_DEFINE_TYPE_WITH_PRIVATE (GtkGears, gtk_gears, GTK_TYPE_GL_AREA)
+
+static gboolean gtk_gears_render (GtkGLArea *area,
+ GdkGLContext *context);
+static void gtk_gears_reshape (GtkGLArea *area,
+ int width,
+ int height);
+static void gtk_gears_realize (GtkWidget *widget);
+static void gtk_gears_unrealize (GtkWidget *widget);
+static gboolean gtk_gears_tick (GtkWidget *widget,
+ GdkFrameClock *frame_clock,
+ gpointer user_data);
+
+static void destroy_gear (struct gear *g);
+
+GtkWidget *
+gtk_gears_new (void)
+{
+ return g_object_new (gtk_gears_get_type (),
+ "has-depth-buffer", TRUE,
+ NULL);
+}
+
+static void
+gtk_gears_init (GtkGears *gears)
+{
+ GtkGearsPrivate *priv = gtk_gears_get_instance_private (gears);
+
+ priv->view_rot[GTK_GEARS_X_AXIS] = 20.0;
+ priv->view_rot[GTK_GEARS_Y_AXIS] = 30.0;
+ priv->view_rot[GTK_GEARS_Z_AXIS] = 20.0;
+
+ priv->LightSourcePosition[0] = 5.0;
+ priv->LightSourcePosition[1] = 5.0;
+ priv->LightSourcePosition[2] = 10.0;
+ priv->LightSourcePosition[3] = 1.0;
+
+ priv->tick = gtk_widget_add_tick_callback (GTK_WIDGET (gears), gtk_gears_tick, gears, NULL);
+}
+
+static void
+gtk_gears_finalize (GObject *obj)
+{
+ GtkGears *gears = GTK_GEARS (obj);
+ GtkGearsPrivate *priv = gtk_gears_get_instance_private (gears);
+
+ gtk_widget_remove_tick_callback (GTK_WIDGET (gears), priv->tick);
+
+ g_clear_object (&priv->fps_label);
+
+ g_clear_pointer (&priv->gear1, destroy_gear);
+ g_clear_pointer (&priv->gear2, destroy_gear);
+ g_clear_pointer (&priv->gear3, destroy_gear);
+
+ G_OBJECT_CLASS (gtk_gears_parent_class)->finalize (obj);
+}
+
+static void
+gtk_gears_class_init (GtkGearsClass *klass)
+{
+ GTK_GL_AREA_CLASS (klass)->render = gtk_gears_render;
+ GTK_GL_AREA_CLASS (klass)->resize = gtk_gears_reshape;
+
+ GTK_WIDGET_CLASS (klass)->realize = gtk_gears_realize;
+ GTK_WIDGET_CLASS (klass)->unrealize = gtk_gears_unrealize;
+
+ G_OBJECT_CLASS (klass)->finalize = gtk_gears_finalize;
+}
+
+/*
+ * Fills a gear vertex.
+ *
+ * @param v the vertex to fill
+ * @param x the x coordinate
+ * @param y the y coordinate
+ * @param z the z coortinate
+ * @param n pointer to the normal table
+ *
+ * @return the operation error code
+ */
+static GearVertex *
+vert (GearVertex *v,
+ GLfloat x,
+ GLfloat y,
+ GLfloat z,
+ GLfloat n[3])
+{
+ v[0][0] = x;
+ v[0][1] = y;
+ v[0][2] = z;
+ v[0][3] = n[0];
+ v[0][4] = n[1];
+ v[0][5] = n[2];
+
+ return v + 1;
+}
+
+static void
+destroy_gear (struct gear *g)
+{
+ g_free (g->strips);
+ g_free (g);
+}
+
+/**
+ * Create a gear wheel.
+ *
+ * @param inner_radius radius of hole at center
+ * @param outer_radius radius at center of teeth
+ * @param width width of gear
+ * @param teeth number of teeth
+ * @param tooth_depth depth of tooth
+ *
+ * @return pointer to the constructed struct gear
+ */
+static struct gear *
+create_gear (GLfloat inner_radius,
+ GLfloat outer_radius,
+ GLfloat width,
+ GLint teeth,
+ GLfloat tooth_depth)
+{
+ GLfloat r0, r1, r2;
+ GLfloat da;
+ GearVertex *v;
+ struct gear *gear;
+ double s[5], c[5];
+ GLfloat normal[3];
+ int cur_strip = 0;
+ int i;
+
+ /* Allocate memory for the gear */
+ gear = g_malloc (sizeof *gear);
+
+ /* Calculate the radii used in the gear */
+ r0 = inner_radius;
+ r1 = outer_radius - tooth_depth / 2.0;
+ r2 = outer_radius + tooth_depth / 2.0;
+
+ da = 2.0 * M_PI / teeth / 4.0;
+
+ /* Allocate memory for the triangle strip information */
+ gear->nstrips = STRIPS_PER_TOOTH * teeth;
+ gear->strips = g_malloc0_n (gear->nstrips, sizeof (*gear->strips));
+
+ /* Allocate memory for the vertices */
+ gear->vertices = g_malloc0_n (VERTICES_PER_TOOTH * teeth, sizeof(*gear->vertices));
+ v = gear->vertices;
+
+ for (i = 0; i < teeth; i++) {
+ /* A set of macros for making the creation of the gears easier */
+#define GEAR_POINT(p, r, da) do { p.x = (r) * c[(da)]; p.y = (r) * s[(da)]; } while(0)
+#define SET_NORMAL(x, y, z) do { \
+ normal[0] = (x); normal[1] = (y); normal[2] = (z); \
+} while(0)
+
+#define GEAR_VERT(v, point, sign) vert((v), p[(point)].x, p[(point)].y, (sign) * width * 0.5, normal)
+
+#define START_STRIP do { \
+ gear->strips[cur_strip].first = v - gear->vertices; \
+} while(0);
+
+#define END_STRIP do { \
+ int _tmp = (v - gear->vertices); \
+ gear->strips[cur_strip].count = _tmp - gear->strips[cur_strip].first; \
+ cur_strip++; \
+} while (0)
+
+#define QUAD_WITH_NORMAL(p1, p2) do { \
+ SET_NORMAL((p[(p1)].y - p[(p2)].y), -(p[(p1)].x - p[(p2)].x), 0); \
+ v = GEAR_VERT(v, (p1), -1); \
+ v = GEAR_VERT(v, (p1), 1); \
+ v = GEAR_VERT(v, (p2), -1); \
+ v = GEAR_VERT(v, (p2), 1); \
+} while(0)
+ struct point {
+ GLfloat x;
+ GLfloat y;
+ };
+
+ /* Create the 7 points (only x,y coords) used to draw a tooth */
+ struct point p[7];
+
+ /* Calculate needed sin/cos for varius angles */
+ sincos(i * 2.0 * G_PI / teeth + da * 0, &s[0], &c[0]);
+ sincos(i * 2.0 * M_PI / teeth + da * 1, &s[1], &c[1]);
+ sincos(i * 2.0 * M_PI / teeth + da * 2, &s[2], &c[2]);
+ sincos(i * 2.0 * M_PI / teeth + da * 3, &s[3], &c[3]);
+ sincos(i * 2.0 * M_PI / teeth + da * 4, &s[4], &c[4]);
+
+ GEAR_POINT(p[0], r2, 1);
+ GEAR_POINT(p[1], r2, 2);
+ GEAR_POINT(p[2], r1, 0);
+ GEAR_POINT(p[3], r1, 3);
+ GEAR_POINT(p[4], r0, 0);
+ GEAR_POINT(p[5], r1, 4);
+ GEAR_POINT(p[6], r0, 4);
+
+ /* Front face */
+ START_STRIP;
+ SET_NORMAL(0, 0, 1.0);
+ v = GEAR_VERT(v, 0, +1);
+ v = GEAR_VERT(v, 1, +1);
+ v = GEAR_VERT(v, 2, +1);
+ v = GEAR_VERT(v, 3, +1);
+ v = GEAR_VERT(v, 4, +1);
+ v = GEAR_VERT(v, 5, +1);
+ v = GEAR_VERT(v, 6, +1);
+ END_STRIP;
+
+ /* Inner face */
+ START_STRIP;
+ QUAD_WITH_NORMAL(4, 6);
+ END_STRIP;
+
+ /* Back face */
+ START_STRIP;
+ SET_NORMAL(0, 0, -1.0);
+ v = GEAR_VERT(v, 6, -1);
+ v = GEAR_VERT(v, 5, -1);
+ v = GEAR_VERT(v, 4, -1);
+ v = GEAR_VERT(v, 3, -1);
+ v = GEAR_VERT(v, 2, -1);
+ v = GEAR_VERT(v, 1, -1);
+ v = GEAR_VERT(v, 0, -1);
+ END_STRIP;
+
+ /* Outer face */
+ START_STRIP;
+ QUAD_WITH_NORMAL(0, 2);
+ END_STRIP;
+
+ START_STRIP;
+ QUAD_WITH_NORMAL(1, 0);
+ END_STRIP;
+
+ START_STRIP;
+ QUAD_WITH_NORMAL(3, 1);
+ END_STRIP;
+
+ START_STRIP;
+ QUAD_WITH_NORMAL(5, 3);
+ END_STRIP;
+ }
+
+ gear->nvertices = (v - gear->vertices);
+
+ return gear;
+}
+
+/**
+ * Multiplies two 4x4 matrices.
+ *
+ * The result is stored in matrix m.
+ *
+ * @param m the first matrix to multiply
+ * @param n the second matrix to multiply
+ */
+static void
+multiply (GLfloat *m, const GLfloat *n)
+{
+ GLfloat tmp[16];
+ const GLfloat *row, *column;
+ div_t d;
+ int i, j;
+
+ for (i = 0; i < 16; i++) {
+ tmp[i] = 0;
+ d = div(i, 4);
+ row = n + d.quot * 4;
+ column = m + d.rem;
+ for (j = 0; j < 4; j++)
+ tmp[i] += row[j] * column[j * 4];
+ }
+ memcpy(m, &tmp, sizeof tmp);
+}
+
+/**
+ * Rotates a 4x4 matrix.
+ *
+ * @param[in,out] m the matrix to rotate
+ * @param angle the angle to rotate
+ * @param x the x component of the direction to rotate to
+ * @param y the y component of the direction to rotate to
+ * @param z the z component of the direction to rotate to
+ */
+static void
+rotate(GLfloat *m, GLfloat angle, GLfloat x, GLfloat y, GLfloat z)
+{
+ double s = sin (angle);
+ double c = cos (angle);
+
+ GLfloat r[16] = {
+ x * x * (1 - c) + c, y * x * (1 - c) + z * s, x * z * (1 - c) - y * s, 0,
+ x * y * (1 - c) - z * s, y * y * (1 - c) + c, y * z * (1 - c) + x * s, 0,
+ x * z * (1 - c) + y * s, y * z * (1 - c) - x * s, z * z * (1 - c) + c, 0,
+ 0, 0, 0, 1
+ };
+
+ multiply(m, r);
+}
+
+/**
+ * Translates a 4x4 matrix.
+ *
+ * @param[in,out] m the matrix to translate
+ * @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 };
+
+ multiply(m, t);
+}
+
+/**
+ * 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,
+ };
+
+ memcpy(m, t, sizeof(t));
+}
+
+/**
+ * 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]};
+
+ memcpy(m, t, sizeof(t));
+}
+
+/**
+ * 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);
+
+ // 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];
+
+ // 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];
+ double sine, cosine, cotangent, deltaZ;
+ GLfloat radians = fovy / 2 * M_PI / 180;
+ identity(tmp);
+
+ 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,
+ GLuint gear_vbo,
+ 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
+gtk_gears_reshape (GtkGLArea *area, int width, int height)
+{
+ GtkGearsPrivate *priv = gtk_gears_get_instance_private ((GtkGears *) area);
+
+ /* Update the projection matrix */
+ perspective (priv->ProjectionMatrix, 60.0, width / (float)height, 1.0, 1024.0);
+
+ /* Set the viewport */
+ glViewport (0, 0, (GLint) width, (GLint) height);
+}
+
+static gboolean
+gtk_gears_render (GtkGLArea *area,
+ GdkGLContext *context)
+{
+ 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 };
+
+ GtkGears *self = GTK_GEARS (area);
+ GtkGearsPrivate *priv = gtk_gears_get_instance_private (self);
+ GLfloat transform[16];
+
+ identity (transform);
+
+ glClearColor (0.0, 0.0, 0.0, 0.0);
+ glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+ /* 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);
+
+ /* Draw the gears */
+ draw_gear (self, priv->gear1, priv->gear_vbo[0], transform, -3.0, -2.0, priv->angle, red);
+ draw_gear (self, priv->gear2, priv->gear_vbo[1], transform, 3.1, -2.0, -2 * priv->angle - 9.0, green);
+ draw_gear (self, priv->gear3, priv->gear_vbo[2], transform, -3.1, 4.2, -2 * priv->angle - 25.0, blue);
+
+ return TRUE;
+}
+
+static const char vertex_shader_gl[] =
+"#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_gl[] =
+"#version 150\n"
+"\n"
+"smooth in vec4 Color;\n"
+"\n"
+"void main(void)\n"
+"{\n"
+" gl_FragColor = Color;\n"
+"}";
+
+static const char vertex_shader_gles[] =
+"attribute vec3 position;\n"
+"attribute vec3 normal;\n"
+"\n"
+"uniform mat4 ModelViewProjectionMatrix;\n"
+"uniform mat4 NormalMatrix;\n"
+"uniform vec4 LightSourcePosition;\n"
+"uniform vec4 MaterialColor;\n"
+"\n"
+"varying 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_gles[] =
+"precision mediump float;\n"
+"varying 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);
+ GtkGearsPrivate *priv = gtk_gears_get_instance_private (gears);
+ GdkGLContext *context;
+ 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);
+ if (gtk_gl_area_get_error (glarea) != NULL)
+ return;
+
+ context = gtk_gl_area_get_context (glarea);
+
+ glEnable (GL_CULL_FACE);
+ glEnable (GL_DEPTH_TEST);
+
+ /* Create the VAO */
+ glGenVertexArrays (1, &vao);
+ glBindVertexArray (vao);
+ priv->vao = vao;
+
+ /* Compile the vertex shader */
+ if (gdk_gl_context_get_use_es (context))
+ p = vertex_shader_gles;
+ else
+ p = vertex_shader_gl;
+ 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 */
+ if (gdk_gl_context_get_use_es (context))
+ p = fragment_shader_gles;
+ else
+ p = fragment_shader_gl;
+ 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);
+ glDeleteShader (v);
+ glDeleteShader (f);
+
+ /* Enable the shaders */
+ glUseProgram(program);
+ priv->program = 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 = create_gear(1.0, 4.0, 1.0, 20, 0.7);
+
+ /* Store the vertices in a vertex buffer object (VBO) */
+ glGenBuffers (1, &(priv->gear_vbo[0]));
+ glBindBuffer (GL_ARRAY_BUFFER, priv->gear_vbo[0]);
+ glBufferData (GL_ARRAY_BUFFER,
+ priv->gear1->nvertices * sizeof(GearVertex),
+ priv->gear1->vertices,
+ GL_STATIC_DRAW);
+
+ priv->gear2 = create_gear(0.5, 2.0, 2.0, 10, 0.7);
+ glGenBuffers (1, &(priv->gear_vbo[1]));
+ glBindBuffer (GL_ARRAY_BUFFER, priv->gear_vbo[1]);
+ glBufferData (GL_ARRAY_BUFFER,
+ priv->gear2->nvertices * sizeof(GearVertex),
+ priv->gear2->vertices,
+ GL_STATIC_DRAW);
+
+ priv->gear3 = create_gear(1.3, 2.0, 0.5, 10, 0.7);
+ glGenBuffers (1, &(priv->gear_vbo[2]));
+ glBindBuffer (GL_ARRAY_BUFFER, priv->gear_vbo[2]);
+ glBufferData (GL_ARRAY_BUFFER,
+ priv->gear3->nvertices * sizeof(GearVertex),
+ priv->gear3->vertices,
+ GL_STATIC_DRAW);
+}
+
+static void
+gtk_gears_unrealize (GtkWidget *widget)
+{
+ GtkGLArea *glarea = GTK_GL_AREA (widget);
+ GtkGearsPrivate *priv = gtk_gears_get_instance_private ((GtkGears *) widget);
+
+ gtk_gl_area_make_current (glarea);
+ if (gtk_gl_area_get_error (glarea) != NULL)
+ return;
+
+ /* Release the resources associated with OpenGL */
+ if (priv->gear_vbo[0] != 0)
+ glDeleteBuffers (1, &(priv->gear_vbo[0]));
+
+ if (priv->gear_vbo[1] != 0)
+ glDeleteBuffers (1, &(priv->gear_vbo[1]));
+
+ if (priv->gear_vbo[2] != 0)
+ glDeleteBuffers (1, &(priv->gear_vbo[2]));
+
+ if (priv->vao != 0)
+ glDeleteVertexArrays (1, &priv->vao);
+
+ if (priv->program != 0)
+ glDeleteProgram (priv->program);
+
+ priv->ModelViewProjectionMatrix_location = 0;
+ priv->NormalMatrix_location = 0;
+ priv->LightSourcePosition_location = 0;
+ priv->MaterialColor_location = 0;
+
+ GTK_WIDGET_CLASS (gtk_gears_parent_class)->unrealize (widget);
+}
+
+static gboolean
+gtk_gears_tick (GtkWidget *widget,
+ GdkFrameClock *frame_clock,
+ gpointer user_data)
+{
+ GtkGears *gears = GTK_GEARS (widget);
+ GtkGearsPrivate *priv = gtk_gears_get_instance_private (gears);
+ GdkFrameTimings *timings, *previous_timings;
+ gint64 previous_frame_time = 0;
+ gint64 frame_time;
+ gint64 history_start, history_len;
+ gint64 frame;
+ char *s;
+
+ frame = gdk_frame_clock_get_frame_counter (frame_clock);
+ frame_time = gdk_frame_clock_get_frame_time (frame_clock);
+
+ if (priv->first_frame_time == 0)
+ {
+ /* No need for changes on first frame */
+ priv->first_frame_time = frame_time;
+ if (priv->fps_label)
+ gtk_label_set_label (priv->fps_label, "FPS: ---");
+ return G_SOURCE_CONTINUE;
+ }
+
+ /* glxgears advances 70 degrees per second, so do the same */
+
+ priv->angle = fmod ((frame_time - priv->first_frame_time) / (double)G_USEC_PER_SEC * 70.0, 360.0);
+
+ gtk_widget_queue_draw (widget);
+
+ history_start = gdk_frame_clock_get_history_start (frame_clock);
+
+ if (priv->fps_label && frame % 60 == 0)
+ {
+ history_len = frame - history_start;
+ if (history_len > 0)
+ {
+ previous_timings = gdk_frame_clock_get_timings (frame_clock, frame - history_len);
+ previous_frame_time = gdk_frame_timings_get_frame_time (previous_timings);
+
+ s = g_strdup_printf ("FPS: %-4.1f", (G_USEC_PER_SEC * history_len) / (double)(frame_time -
previous_frame_time));
+ gtk_label_set_label (priv->fps_label, s);
+ g_free (s);
+ }
+ }
+
+ timings = gdk_frame_clock_get_current_timings (frame_clock);
+ previous_timings = gdk_frame_clock_get_timings (frame_clock,
+ gdk_frame_timings_get_frame_counter (timings) - 1);
+ if (previous_timings != NULL)
+ previous_frame_time = gdk_frame_timings_get_frame_time (previous_timings);
+
+ return G_SOURCE_CONTINUE;
+}
+
+void
+gtk_gears_set_axis (GtkGears *gears, int axis, double value)
+{
+ GtkGearsPrivate *priv = gtk_gears_get_instance_private (gears);
+
+ if (axis < 0 || axis >= GTK_GEARS_N_AXIS)
+ return;
+
+ priv->view_rot[axis] = value;
+
+ gtk_widget_queue_draw (GTK_WIDGET (gears));
+}
+
+double
+gtk_gears_get_axis (GtkGears *gears, int axis)
+{
+ GtkGearsPrivate *priv = gtk_gears_get_instance_private (gears);
+
+ if (axis < 0 || axis >= GTK_GEARS_N_AXIS)
+ return 0.0;
+
+ return priv->view_rot[axis];
+}
+
+void
+gtk_gears_set_fps_label (GtkGears *gears, GtkLabel *label)
+{
+ GtkGearsPrivate *priv = gtk_gears_get_instance_private (gears);
+
+ if (label)
+ g_object_ref (label);
+
+ g_clear_object (&priv->fps_label);
+
+ priv->fps_label = label;
+}
diff --git a/demos/gtk-demo/gtkgears.h b/demos/gtk-demo/gtkgears.h
new file mode 100644
index 0000000..0109723
--- /dev/null
+++ b/demos/gtk-demo/gtkgears.h
@@ -0,0 +1,48 @@
+#ifndef __GTK_GEARS_H__
+#define __GTK_GEARS_H__
+
+#include <gtk/gtk.h>
+
+G_BEGIN_DECLS
+
+enum {
+ GTK_GEARS_X_AXIS,
+ GTK_GEARS_Y_AXIS,
+ GTK_GEARS_Z_AXIS,
+
+ GTK_GEARS_N_AXIS
+};
+
+#define GTK_TYPE_GEARS (gtk_gears_get_type ())
+#define GTK_GEARS(inst) (G_TYPE_CHECK_INSTANCE_CAST ((inst), \
+ GTK_TYPE_GEARS, \
+ GtkGears))
+#define GTK_IS_GEARS(inst) (G_TYPE_CHECK_INSTANCE_TYPE ((inst), \
+ GTK_TYPE_GEARS))
+
+typedef struct _GtkGears GtkGears;
+typedef struct _GtkGearsClass GtkGearsClass;
+
+struct _GtkGears {
+ GtkGLArea parent;
+};
+
+struct _GtkGearsClass {
+ GtkGLAreaClass parent_class;
+};
+
+GType gtk_gears_get_type (void) G_GNUC_CONST;
+
+GtkWidget *gtk_gears_new (void);
+void gtk_gears_set_axis (GtkGears *gears,
+ int axis,
+ double value);
+double gtk_gears_get_axis (GtkGears *gears,
+ int axis);
+void gtk_gears_set_fps_label (GtkGears *gears,
+ GtkLabel *label);
+
+
+G_END_DECLS
+
+#endif /* __GTK_GEARS_H__ */
diff --git a/demos/gtk-demo/meson.build b/demos/gtk-demo/meson.build
index f4c3613..ed2e58c 100644
--- a/demos/gtk-demo/meson.build
+++ b/demos/gtk-demo/meson.build
@@ -94,7 +94,9 @@ gtkdemo_resources = gnome.compile_resources('gtkdemo_resources',
source_dir: '.')
executable('gtk4-demo',
- 'main.c', 'gtkfishbowl.c', 'fontplane.c', 'script-names.c', 'language-names.c', demos, demos_h,
gtkdemo_resources,
+ 'main.c', 'gtkfishbowl.c', 'fontplane.c', 'script-names.c', 'language-names.c',
+ 'gtkgears.c',
+ demos, demos_h, gtkdemo_resources,
c_args: gtkdemo_args,
dependencies: gtkdemo_deps,
include_directories: confinc,
diff --git a/demos/gtk-demo/widgetbowl.c b/demos/gtk-demo/widgetbowl.c
index 1ac2139..aadee03 100644
--- a/demos/gtk-demo/widgetbowl.c
+++ b/demos/gtk-demo/widgetbowl.c
@@ -8,6 +8,7 @@
#include <gtk/gtk.h>
#include "gtkfishbowl.h"
+#include "gtkgears.h"
const char *const css =
".blurred-button {"
@@ -80,6 +81,16 @@ create_label (void)
return w;
}
+static GtkWidget *
+create_gears (void)
+{
+ GtkWidget *w = gtk_gears_new ();
+
+ gtk_widget_set_size_request (w, 100, 100);
+
+ return w;
+}
+
static const struct {
const char *name;
GtkWidget * (*create_func) (void);
@@ -91,6 +102,7 @@ static const struct {
{ "Label" , create_label },
{ "Spinner" , create_spinner },
{ "Spinbutton", create_spinbutton },
+ { "Gears", create_gears },
};
static int selected_widget_type = -1;
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