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-rw-r--r--AUTHORS1
-rw-r--r--src/library.js2
-rw-r--r--src/library_gl.js219
-rw-r--r--tests/hello_world_gles_full.c742
-rwxr-xr-xtests/runner.py20
-rw-r--r--tools/cache.py5
6 files changed, 890 insertions, 99 deletions
diff --git a/AUTHORS b/AUTHORS
index 296d4150..0741022f 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -52,4 +52,5 @@ a license to everyone to use it as detailed in LICENSE.)
* Roger Braun <roger@rogerbraun.net>
* Vladimir Vukicevic <vladimir@pobox.com> (copyright owned by Mozilla Foundation)
* Lorant Pinter <lorant.pinter@prezi.com>
+* Tobias Doerffel <tobias.doerffel@gmail.com>
diff --git a/src/library.js b/src/library.js
index c40921ae..6ba6dab3 100644
--- a/src/library.js
+++ b/src/library.js
@@ -6107,7 +6107,7 @@ LibraryManager.library = {
setjmp__inline: function(env) {
// Save the label
- return '(tempInt = setjmpId++, mySetjmpIds[tempInt] = 1, setjmpLabels[tempInt] = label,' + makeSetValue(env, '0', 'tempInt', 'i32') + ', 0)';
+ return '(tempInt = setjmpId++, mySetjmpIds[tempInt] = 1, setjmpLabels[tempInt] = label,' + makeSetValue(env, '0', 'tempInt', 'i32', undefined, undefined, undefined, undefined, ',') + ', 0)';
},
longjmp: function(env, value) {
diff --git a/src/library_gl.js b/src/library_gl.js
index 4977d2e9..c6007809 100644
--- a/src/library_gl.js
+++ b/src/library_gl.js
@@ -21,7 +21,6 @@ var LibraryGL = {
#if FULL_ES2
clientBuffers: [],
- enabledClientBuffers: [],
#endif
currArrayBuffer: 0,
currElementArrayBuffer: 0,
@@ -59,6 +58,65 @@ var LibraryGL = {
return ret;
},
+ // Temporary buffers
+ MAX_TEMP_BUFFER_SIZE: {{{ GL_MAX_TEMP_BUFFER_SIZE }}},
+ tempBufferIndexLookup: null,
+ tempVertexBuffers: null,
+ tempIndexBuffers: null,
+ tempQuadIndexBuffer: null,
+
+ generateTempBuffers: function(quads) {
+ this.tempBufferIndexLookup = new Uint8Array(this.MAX_TEMP_BUFFER_SIZE+1);
+ this.tempVertexBuffers = [];
+ this.tempIndexBuffers = [];
+ var last = -1, curr = -1;
+ var size = 1;
+ for (var i = 0; i <= this.MAX_TEMP_BUFFER_SIZE; i++) {
+ if (i > size) {
+ size <<= 1;
+ }
+ if (size != last) {
+ curr++;
+ this.tempVertexBuffers[curr] = Module.ctx.createBuffer();
+ Module.ctx.bindBuffer(Module.ctx.ARRAY_BUFFER, this.tempVertexBuffers[curr]);
+ Module.ctx.bufferData(Module.ctx.ARRAY_BUFFER, size, Module.ctx.DYNAMIC_DRAW);
+ Module.ctx.bindBuffer(Module.ctx.ARRAY_BUFFER, null);
+ this.tempIndexBuffers[curr] = Module.ctx.createBuffer();
+ Module.ctx.bindBuffer(Module.ctx.ELEMENT_ARRAY_BUFFER, this.tempIndexBuffers[curr]);
+ Module.ctx.bufferData(Module.ctx.ELEMENT_ARRAY_BUFFER, size, Module.ctx.DYNAMIC_DRAW);
+ Module.ctx.bindBuffer(Module.ctx.ELEMENT_ARRAY_BUFFER, null);
+ last = size;
+ }
+ this.tempBufferIndexLookup[i] = curr;
+ }
+
+ if (quads) {
+ // GL_QUAD indexes can be precalculated
+ this.tempQuadIndexBuffer = Module.ctx.createBuffer();
+ Module.ctx.bindBuffer(Module.ctx.ELEMENT_ARRAY_BUFFER, this.tempQuadIndexBuffer);
+ var numIndexes = this.MAX_TEMP_BUFFER_SIZE >> 1;
+ var quadIndexes = new Uint16Array(numIndexes);
+ var i = 0, v = 0;
+ while (1) {
+ quadIndexes[i++] = v;
+ if (i >= numIndexes) break;
+ quadIndexes[i++] = v+1;
+ if (i >= numIndexes) break;
+ quadIndexes[i++] = v+2;
+ if (i >= numIndexes) break;
+ quadIndexes[i++] = v;
+ if (i >= numIndexes) break;
+ quadIndexes[i++] = v+2;
+ if (i >= numIndexes) break;
+ quadIndexes[i++] = v+3;
+ if (i >= numIndexes) break;
+ v += 4;
+ }
+ Module.ctx.bufferData(Module.ctx.ELEMENT_ARRAY_BUFFER, quadIndexes, Module.ctx.STATIC_DRAW);
+ Module.ctx.bindBuffer(Module.ctx.ELEMENT_ARRAY_BUFFER, null);
+ }
+ },
+
// Linear lookup in one of the tables (buffers, programs, etc.). TODO: consider using a weakmap to make this faster, if it matters
scan: function(table, object) {
for (var item in table) {
@@ -207,19 +265,34 @@ var LibraryGL = {
return size * typeSize * count;
},
+ usedTempBuffers: [],
+
preDrawHandleClientVertexAttribBindings: function(count) {
GL.resetBufferBinding = false;
+
+ var used = GL.usedTempBuffers;
+ used.length = 0;
+
+ // TODO: initial pass to detect ranges we need to upload, might not need an upload per attrib
for (var i = 0; i < GL.maxVertexAttribs; ++i) {
- if (!GL.enabledClientBuffers[i] || !GL.clientBuffers[i]) continue;
-
- GL.resetBufferBinding = true;
-
var cb = GL.clientBuffers[i];
-
- var buf = Module.ctx.createBuffer();
+ if (!cb.enabled) continue;
+
+ GL.resetBufferBinding = true;
+
+ var size = GL.calcBufLength(cb.size, cb.type, cb.stride, count);
+ var index = GL.tempBufferIndexLookup[size];
+ var buf;
+ do {
+#if ASSERTIONS
+ assert(index < GL.tempVertexBuffers.length);
+#endif
+ buf = GL.tempVertexBuffers[index++];
+ } while (used.indexOf(buf) >= 0);
+ used.push(buf);
Module.ctx.bindBuffer(Module.ctx.ARRAY_BUFFER, buf);
Module.ctx.bufferData(Module.ctx.ARRAY_BUFFER,
- HEAPU8.subarray(cb.ptr, cb.ptr + GL.calcBufLength(cb.size, cb.type, cb.stride, count)),
+ HEAPU8.subarray(cb.ptr, cb.ptr + size),
Module.ctx.DYNAMIC_DRAW);
Module.ctx.vertexAttribPointer(i, cb.size, cb.type, cb.normalized, cb.stride, 0);
}
@@ -239,6 +312,13 @@ var LibraryGL = {
if (!Module.useWebGL) return; // an app might link both gl and 2d backends
GL.maxVertexAttribs = Module.ctx.getParameter(Module.ctx.MAX_VERTEX_ATTRIBS);
+#if FULL_ES2
+ for (var i = 0; i < GL.maxVertexAttribs; i++) {
+ GL.clientBuffers[i] = { enabled: false, size: 0, type: 0, normalized: 0, stride: 0, ptr: 0 };
+ }
+
+ GL.generateTempBuffers();
+#endif
GL.compressionExt = Module.ctx.getExtension('WEBGL_compressed_texture_s3tc') ||
Module.ctx.getExtension('MOZ_WEBGL_compressed_texture_s3tc') ||
@@ -612,7 +692,7 @@ var LibraryGL = {
glGetVertexAttribfv: function(index, pname, params) {
#if FULL_ES2
- if (GL.clientBuffers[index]) {
+ if (GL.clientBuffers[index].enabled) {
Module.printErr("glGetVertexAttribfv on client-side array: not supported, bad data returned");
}
#endif
@@ -628,7 +708,7 @@ var LibraryGL = {
glGetVertexAttribiv: function(index, pname, params) {
#if FULL_ES2
- if (GL.clientBuffers[index]) {
+ if (GL.clientBuffers[index].enabled) {
Module.printErr("glGetVertexAttribiv on client-side array: not supported, bad data returned");
}
#endif
@@ -644,7 +724,7 @@ var LibraryGL = {
glGetVertexAttribPointerv: function(index, pname, pointer) {
#if FULL_ES2
- if (GL.clientBuffers[index]) {
+ if (GL.clientBuffers[index].enabled) {
Module.printErr("glGetVertexAttribPointer on client-side array: not supported, bad data returned");
}
#endif
@@ -1693,62 +1773,6 @@ var LibraryGL = {
this.modifiedClientAttributes = true;
},
- // Temporary buffers
- MAX_TEMP_BUFFER_SIZE: {{{ GL_MAX_TEMP_BUFFER_SIZE }}},
- tempBufferIndexLookup: null,
- tempVertexBuffers: null,
- tempIndexBuffers: null,
- tempQuadIndexBuffer: null,
-
- generateTempBuffers: function() {
- this.tempBufferIndexLookup = new Uint8Array(this.MAX_TEMP_BUFFER_SIZE+1);
- this.tempVertexBuffers = [];
- this.tempIndexBuffers = [];
- var last = -1, curr = -1;
- var size = 1;
- for (var i = 0; i <= this.MAX_TEMP_BUFFER_SIZE; i++) {
- if (i > size) {
- size <<= 1;
- }
- if (size != last) {
- curr++;
- this.tempVertexBuffers[curr] = Module.ctx.createBuffer();
- Module.ctx.bindBuffer(Module.ctx.ARRAY_BUFFER, this.tempVertexBuffers[curr]);
- Module.ctx.bufferData(Module.ctx.ARRAY_BUFFER, size, Module.ctx.DYNAMIC_DRAW);
- Module.ctx.bindBuffer(Module.ctx.ARRAY_BUFFER, null);
- this.tempIndexBuffers[curr] = Module.ctx.createBuffer();
- Module.ctx.bindBuffer(Module.ctx.ELEMENT_ARRAY_BUFFER, this.tempIndexBuffers[curr]);
- Module.ctx.bufferData(Module.ctx.ELEMENT_ARRAY_BUFFER, size, Module.ctx.DYNAMIC_DRAW);
- Module.ctx.bindBuffer(Module.ctx.ELEMENT_ARRAY_BUFFER, null);
- last = size;
- }
- this.tempBufferIndexLookup[i] = curr;
- }
- // GL_QUAD indexes can be precalculated
- this.tempQuadIndexBuffer = Module.ctx.createBuffer();
- Module.ctx.bindBuffer(Module.ctx.ELEMENT_ARRAY_BUFFER, this.tempQuadIndexBuffer);
- var numIndexes = this.MAX_TEMP_BUFFER_SIZE >> 1;
- var quadIndexes = new Uint16Array(numIndexes);
- var i = 0, v = 0;
- while (1) {
- quadIndexes[i++] = v;
- if (i >= numIndexes) break;
- quadIndexes[i++] = v+1;
- if (i >= numIndexes) break;
- quadIndexes[i++] = v+2;
- if (i >= numIndexes) break;
- quadIndexes[i++] = v;
- if (i >= numIndexes) break;
- quadIndexes[i++] = v+2;
- if (i >= numIndexes) break;
- quadIndexes[i++] = v+3;
- if (i >= numIndexes) break;
- v += 4;
- }
- Module.ctx.bufferData(Module.ctx.ELEMENT_ARRAY_BUFFER, quadIndexes, Module.ctx.STATIC_DRAW);
- Module.ctx.bindBuffer(Module.ctx.ELEMENT_ARRAY_BUFFER, null);
- },
-
// Renderers
addRendererComponent: function(name, size, type) {
if (!this.rendererComponents[name]) {
@@ -1969,8 +1993,8 @@ var LibraryGL = {
if (!GL.currArrayBuffer) {
var start = GL.immediate.firstVertex*GL.immediate.stride;
var end = GL.immediate.lastVertex*GL.immediate.stride;
- assert(end <= GL.immediate.MAX_TEMP_BUFFER_SIZE, 'too much vertex data');
- arrayBuffer = GL.immediate.tempVertexBuffers[GL.immediate.tempBufferIndexLookup[end]];
+ assert(end <= GL.MAX_TEMP_BUFFER_SIZE, 'too much vertex data');
+ arrayBuffer = GL.tempVertexBuffers[GL.tempBufferIndexLookup[end]];
// TODO: consider using the last buffer we bound, if it was larger. downside is larger buffer, but we might avoid rebinding and preparing
} else {
arrayBuffer = GL.currArrayBuffer;
@@ -2161,12 +2185,12 @@ var LibraryGL = {
this.rendererCache = this.rendererCacheItemTemplate.slice();
// Buffers for data
- this.tempData = new Float32Array(this.MAX_TEMP_BUFFER_SIZE >> 2);
- this.indexData = new Uint16Array(this.MAX_TEMP_BUFFER_SIZE >> 1);
+ this.tempData = new Float32Array(GL.MAX_TEMP_BUFFER_SIZE >> 2);
+ this.indexData = new Uint16Array(GL.MAX_TEMP_BUFFER_SIZE >> 1);
this.vertexDataU8 = new Uint8Array(this.tempData.buffer);
- this.generateTempBuffers();
+ GL.generateTempBuffers(true);
this.clientColor = new Float32Array([1, 1, 1, 1]);
},
@@ -2209,7 +2233,7 @@ var LibraryGL = {
#if ASSERTIONS
Runtime.warnOnce('Unpacking/restriding attributes, this is not fast');
#endif
- if (!GL.immediate.restrideBuffer) GL.immediate.restrideBuffer = _malloc(GL.immediate.MAX_TEMP_BUFFER_SIZE);
+ if (!GL.immediate.restrideBuffer) GL.immediate.restrideBuffer = _malloc(GL.MAX_TEMP_BUFFER_SIZE);
start = GL.immediate.restrideBuffer;
#if ASSERTIONS
assert(start % 4 == 0);
@@ -2224,7 +2248,7 @@ var LibraryGL = {
bytes += size;
}
#if ASSERTIONS
- assert(count*bytes <= GL.immediate.MAX_TEMP_BUFFER_SIZE);
+ assert(count*bytes <= GL.MAX_TEMP_BUFFER_SIZE);
#endif
// copy out the data (we need to know the stride for that, and define attribute.pointer
for (var i = 0; i < attributes.length; i++) {
@@ -2298,8 +2322,8 @@ var LibraryGL = {
}
if (!GL.currElementArrayBuffer) {
// If no element array buffer is bound, then indices is a literal pointer to clientside data
- assert(numProvidedIndexes << 1 <= GL.immediate.MAX_TEMP_BUFFER_SIZE, 'too many immediate mode indexes (a)');
- var indexBuffer = GL.immediate.tempIndexBuffers[GL.immediate.tempBufferIndexLookup[numProvidedIndexes << 1]];
+ assert(numProvidedIndexes << 1 <= GL.MAX_TEMP_BUFFER_SIZE, 'too many immediate mode indexes (a)');
+ var indexBuffer = GL.tempIndexBuffers[GL.tempBufferIndexLookup[numProvidedIndexes << 1]];
Module.ctx.bindBuffer(Module.ctx.ELEMENT_ARRAY_BUFFER, indexBuffer);
Module.ctx.bufferSubData(Module.ctx.ELEMENT_ARRAY_BUFFER, 0, {{{ makeHEAPView('U16', 'ptr', 'ptr + (numProvidedIndexes << 1)') }}});
ptr = 0;
@@ -2314,8 +2338,8 @@ var LibraryGL = {
ptr = GL.immediate.firstVertex*3;
var numQuads = numVertexes / 4;
numIndexes = numQuads * 6; // 0 1 2, 0 2 3 pattern
- assert(ptr + (numIndexes << 1) <= GL.immediate.MAX_TEMP_BUFFER_SIZE, 'too many immediate mode indexes (b)');
- Module.ctx.bindBuffer(Module.ctx.ELEMENT_ARRAY_BUFFER, this.tempQuadIndexBuffer);
+ assert(ptr + (numIndexes << 1) <= GL.MAX_TEMP_BUFFER_SIZE, 'too many immediate mode indexes (b)');
+ Module.ctx.bindBuffer(Module.ctx.ELEMENT_ARRAY_BUFFER, GL.tempQuadIndexBuffer);
emulatedElementArrayBuffer = true;
}
@@ -2369,7 +2393,7 @@ var LibraryGL = {
GL.immediate.vertexData[GL.immediate.vertexCounter++] = y;
GL.immediate.vertexData[GL.immediate.vertexCounter++] = z || 0;
#if ASSERTIONS
- assert(GL.immediate.vertexCounter << 2 < GL.immediate.MAX_TEMP_BUFFER_SIZE);
+ assert(GL.immediate.vertexCounter << 2 < GL.MAX_TEMP_BUFFER_SIZE);
#endif
GL.immediate.addRendererComponent(GL.immediate.VERTEX, 3, Module.ctx.FLOAT);
},
@@ -2849,15 +2873,24 @@ var LibraryGL = {
glShadeModel: function() { Runtime.warnOnce('TODO: glShadeModel') },
+ // GLES2 emulation
+
glVertexAttribPointer__sig: 'viiiiii',
glVertexAttribPointer: function(index, size, type, normalized, stride, ptr) {
#if FULL_ES2
+ var cb = GL.clientBuffers[index];
+#if ASSERTIONS
+ assert(cb, index);
+#endif
if (!GL.currArrayBuffer) {
- GL.clientBuffers[index] = { size: size, type: type, normalized: normalized, stride: stride, ptr: ptr };
+ cb.size = size;
+ cb.type = type;
+ cb.normalized = normalized;
+ cb.stride = stride;
+ cb.ptr = ptr;
return;
}
-
- GL.clientBuffers[index] = null;
+ cb.enabled = false;
#endif
Module.ctx.vertexAttribPointer(index, size, type, normalized, stride, ptr);
},
@@ -2865,7 +2898,11 @@ var LibraryGL = {
glEnableVertexAttribArray__sig: 'vi',
glEnableVertexAttribArray: function(index) {
#if FULL_ES2
- GL.enabledClientBuffers[index] = true;
+ var cb = GL.clientBuffers[index];
+#if ASSERTIONS
+ assert(cb, index);
+#endif
+ cb.enabled = true;
#endif
Module.ctx.enableVertexAttribArray(index);
},
@@ -2873,7 +2910,11 @@ var LibraryGL = {
glDisableVertexAttribArray__sig: 'vi',
glDisableVertexAttribArray: function(index) {
#if FULL_ES2
- GL.enabledClientBuffers[index] = false;
+ var cb = GL.clientBuffers[index];
+#if ASSERTIONS
+ assert(cb, index);
+#endif
+ cb.enabled = false;
#endif
Module.ctx.disableVertexAttribArray(index);
},
@@ -2881,7 +2922,7 @@ var LibraryGL = {
glDrawArrays: function(mode, first, count) {
#if FULL_ES2
// bind any client-side buffers
- GL.preDrawHandleClientVertexAttribBindings(count);
+ GL.preDrawHandleClientVertexAttribBindings(first + count);
#endif
Module.ctx.drawArrays(mode, first, count);
@@ -2895,10 +2936,11 @@ var LibraryGL = {
#if FULL_ES2
var buf;
if (!GL.currElementArrayBuffer) {
- buf = Module.ctx.createBuffer();
+ var size = GL.calcBufLength(1, type, 0, count);
+ buf = GL.tempIndexBuffers[GL.tempBufferIndexLookup[size]];
Module.ctx.bindBuffer(Module.ctx.ELEMENT_ARRAY_BUFFER, buf);
Module.ctx.bufferData(Module.ctx.ELEMENT_ARRAY_BUFFER,
- HEAPU8.subarray(indices, indices + GL.calcBufLength(1, type, 0, count)),
+ HEAPU8.subarray(indices, indices + size),
Module.ctx.DYNAMIC_DRAW);
// the index is now 0
indices = 0;
@@ -2915,17 +2957,18 @@ var LibraryGL = {
if (!GL.currElementArrayBuffer) {
Module.ctx.bindBuffer(Module.ctx.ELEMENT_ARRAY_BUFFER, null);
- Module.ctx.deleteBuffer(buf);
}
#endif
},
// signatures of simple pass-through functions, see later
+
glActiveTexture__sig: 'vi',
glCheckFramebufferStatus__sig: 'ii',
glRenderbufferStorage__sig: 'viiii',
// Open GLES1.1 compatibility
+
glGenFramebuffersOES : 'glGenFramebuffers',
glGenRenderbuffersOES : 'glGenRenderbuffers',
glBindFramebufferOES : 'glBindFramebuffer',
diff --git a/tests/hello_world_gles_full.c b/tests/hello_world_gles_full.c
new file mode 100644
index 00000000..cca66506
--- /dev/null
+++ b/tests/hello_world_gles_full.c
@@ -0,0 +1,742 @@
+/*
+ * 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
+ */
+
+#define GL_GLEXT_PROTOTYPES
+#define EGL_EGLEXT_PROTOTYPES
+
+#define _GNU_SOURCE
+
+#include <math.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/time.h>
+#include <unistd.h>
+#ifdef __APPLE__
+#include <OpenGL/gl.h>
+#include <Glut/glut.h>
+#else
+#include <GL/gl.h>
+#include <GL/glut.h>
+#endif
+
+#define STRIPS_PER_TOOTH 7
+#define VERTICES_PER_TOOTH 34
+#define GEAR_VERTEX_STRIDE 6
+
+#ifndef HAVE_BUILTIN_SINCOS
+#define sincos _sincos
+static void
+sincos (double a, double *s, double *c)
+{
+ *s = sin (a);
+ *c = cos (a);
+}
+#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;
+ /** The Vertex Buffer Object holding the vertices in the graphics card */
+ GLuint vbo;
+};
+
+/** The view rotation [x, y, z] */
+static GLfloat view_rot[3] = { 20.0, 30.0, 0.0 };
+/** The gears */
+static struct gear *gear1, *gear2, *gear3;
+/** The current gear rotation angle */
+static GLfloat angle = 0.0;
+/** The location of the shader uniforms */
+static GLuint ModelViewProjectionMatrix_location,
+ NormalMatrix_location,
+ LightSourcePosition_location,
+ MaterialColor_location;
+/** The projection matrix */
+static GLfloat ProjectionMatrix[16];
+/** The direction of the directional light for the scene */
+static const GLfloat LightSourcePosition[4] = { 5.0, 5.0, 10.0, 1.0};
+
+/**
+ * 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;
+}
+
+/**
+ * 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 = malloc(sizeof *gear);
+ if (gear == NULL)
+ return NULL;
+
+ /* 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 = calloc(gear->nstrips, sizeof (*gear->strips));
+
+ /* Allocate memory for the vertices */
+ gear->vertices = calloc(VERTICES_PER_TOOTH * teeth, sizeof(*gear->vertices));
+ v = gear->vertices;
+
+ for (i = 0; i < teeth; i++) {
+ /* Calculate needed sin/cos for varius angles */
+ sincos(i * 2.0 * M_PI / teeth, &s[0], &c[0]);
+ sincos(i * 2.0 * M_PI / teeth + da, &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]);
+
+ /* A set of macros for making the creation of the gears easier */
+#define GEAR_POINT(r, da) { (r) * c[(da)], (r) * s[(da)] }
+#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] = {
+ GEAR_POINT(r2, 1), // 0
+ GEAR_POINT(r2, 2), // 1
+ GEAR_POINT(r1, 0), // 2
+ GEAR_POINT(r1, 3), // 3
+ GEAR_POINT(r0, 0), // 4
+ GEAR_POINT(r1, 4), // 5
+ GEAR_POINT(r0, 4), // 6
+ };
+
+ /* 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);
+
+ /* Store the vertices in a vertex buffer object (VBO) */
+ glGenBuffers(1, &gear->vbo);
+ glBindBuffer(GL_ARRAY_BUFFER, gear->vbo);
+ glBufferData(GL_ARRAY_BUFFER, gear->nvertices * sizeof(GearVertex),
+ gear->vertices, GL_STATIC_DRAW);
+
+ 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, c;
+
+ sincos(angle, &s, &c);
+ 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];
+ 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(struct gear *gear, GLfloat *transform,
+ GLfloat x, GLfloat y, GLfloat angle, const GLfloat color[4])
+{
+ GLfloat model_view[16];
+ GLfloat normal_matrix[16];
+ GLfloat model_view_projection[16];
+
+ /* Translate and rotate the gear */
+ memcpy(model_view, transform, sizeof (model_view));
+ translate(model_view, x, y, 0);
+ rotate(model_view, 2 * M_PI * angle / 360.0, 0, 0, 1);
+
+ /* Create and set the ModelViewProjectionMatrix */
+ memcpy(model_view_projection, ProjectionMatrix, sizeof(model_view_projection));
+ multiply(model_view_projection, model_view);
+
+ glUniformMatrix4fv(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(NormalMatrix_location, 1, GL_FALSE, normal_matrix);
+
+ /* Set the gear color */
+ glUniform4fv(MaterialColor_location, 1, color);
+
+ /* Set the vertex buffer object to use */
+ glBindBuffer(GL_ARRAY_BUFFER, 0);
+
+ /* Set up the position of the attributes in the vertex buffer object */
+ glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE,
+ 6 * sizeof(GLfloat), *gear->vertices);
+ glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE,
+ 6 * sizeof(GLfloat), ((float*)*gear->vertices) + 3*4);
+ /* Enable the attributes */
+ glEnableVertexAttribArray(0);
+ glEnableVertexAttribArray(1);
+
+ /* Draw the triangle strips that comprise the gear */
+ int n;
+ 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);
+}
+
+/**
+ * Draws the gears.
+ */
+static void
+gears_draw(void)
+{
+ const static GLfloat red[4] = { 0.8, 0.1, 0.0, 1.0 };
+ const static GLfloat green[4] = { 0.0, 0.8, 0.2, 1.0 };
+ const static GLfloat blue[4] = { 0.2, 0.2, 1.0, 1.0 };
+ 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 * M_PI * view_rot[0] / 360.0, 1, 0, 0);
+ rotate(transform, 2 * M_PI * view_rot[1] / 360.0, 0, 1, 0);
+ rotate(transform, 2 * M_PI * view_rot[2] / 360.0, 0, 0, 1);
+
+ /* Draw the gears */
+ draw_gear(gear1, transform, -3.0, -2.0, angle, red);
+ draw_gear(gear2, transform, 3.1, -2.0, -2 * angle - 9.0, green);
+ draw_gear(gear3, transform, -3.1, 4.2, -2 * angle - 25.0, blue);
+
+ glutSwapBuffers();
+}
+
+/**
+ * Handles a new window size or exposure.
+ *
+ * @param width the window width
+ * @param height the window height
+ */
+static void
+gears_reshape(int width, int height)
+{
+ /* Update the projection matrix */
+ perspective(ProjectionMatrix, 60.0, width / (float)height, 1.0, 1024.0);
+
+ /* Set the viewport */
+ glViewport(0, 0, (GLint) width, (GLint) height);
+}
+
+/**
+ * Handles special glut events.
+ *
+ * @param special the event to handle.
+ */
+static void
+gears_special(int special, int crap, int morecrap)
+{
+ switch (special) {
+ case GLUT_KEY_LEFT:
+ view_rot[1] += 5.0;
+ break;
+ case GLUT_KEY_RIGHT:
+ view_rot[1] -= 5.0;
+ break;
+ case GLUT_KEY_UP:
+ view_rot[0] += 5.0;
+ break;
+ case GLUT_KEY_DOWN:
+ view_rot[0] -= 5.0;
+ break;
+ case GLUT_KEY_F11:
+ glutFullScreen();
+ break;
+ }
+}
+
+static void
+gears_idle(void)
+{
+ static int frames = 0;
+ static double tRot0 = -1.0, tRate0 = -1.0;
+ double dt, t = glutGet(GLUT_ELAPSED_TIME) / 1000.0;
+
+ if (tRot0 < 0.0)
+ tRot0 = t;
+ dt = t - tRot0;
+ tRot0 = t;
+
+ /* advance rotation for next frame */
+ angle += 70.0 * dt; /* 70 degrees per second */
+ if (angle > 3600.0)
+ angle -= 3600.0;
+
+ glutPostRedisplay();
+ frames++;
+
+ if (tRate0 < 0.0)
+ tRate0 = t;
+ if (t - tRate0 >= 5.0) {