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authorBrian Paul <brianp@vmware.com>2009-05-22 13:12:28 -0600
committerBrian Paul <brianp@vmware.com>2009-05-22 13:12:28 -0600
commit891a2bdd7d11086712500cf916efbc1b733f094b (patch)
tree192b936acfed2b79fbde6dfbc947043bd4933112
parent96370113f1a3580ed2a8ef2fb427f37afd7432f8 (diff)
demos: extend glsl/multitex.c to use a vertex buffer object
-rw-r--r--progs/glsl/multitex.c93
1 files changed, 87 insertions, 6 deletions
diff --git a/progs/glsl/multitex.c b/progs/glsl/multitex.c
index b4be463787..1a1c63aaf4 100644
--- a/progs/glsl/multitex.c
+++ b/progs/glsl/multitex.c
@@ -51,6 +51,8 @@ static GLfloat Xrot = 0.0, Yrot = .0, Zrot = 0.0;
static GLfloat EyeDist = 10;
static GLboolean Anim = GL_TRUE;
static GLboolean UseArrays = GL_TRUE;
+static GLboolean UseVBO = GL_TRUE;
+static GLuint VBO = 0;
static GLint VertCoord_attr = -1, TexCoord0_attr = -1, TexCoord1_attr = -1;
@@ -76,28 +78,81 @@ static const GLfloat VertCoords[4][2] = {
};
+
+static void
+SetupVertexBuffer(void)
+{
+ glGenBuffersARB_func(1, &VBO);
+ glBindBufferARB_func(GL_ARRAY_BUFFER_ARB, VBO);
+
+ glBufferDataARB_func(GL_ARRAY_BUFFER_ARB,
+ sizeof(VertCoords) +
+ sizeof(Tex0Coords) +
+ sizeof(Tex1Coords),
+ NULL,
+ GL_STATIC_DRAW_ARB);
+
+ /* non-interleaved vertex arrays */
+
+ glBufferSubDataARB_func(GL_ARRAY_BUFFER_ARB,
+ 0, /* offset */
+ sizeof(VertCoords), /* size */
+ VertCoords); /* data */
+
+ glBufferSubDataARB_func(GL_ARRAY_BUFFER_ARB,
+ sizeof(VertCoords), /* offset */
+ sizeof(Tex0Coords), /* size */
+ Tex0Coords); /* data */
+
+ glBufferSubDataARB_func(GL_ARRAY_BUFFER_ARB,
+ sizeof(VertCoords) +
+ sizeof(Tex0Coords), /* offset */
+ sizeof(Tex1Coords), /* size */
+ Tex1Coords); /* data */
+
+ glBindBufferARB_func(GL_ARRAY_BUFFER_ARB, 0);
+}
+
+
static void
DrawPolygonArray(void)
{
+ void *vertPtr, *tex0Ptr, *tex1Ptr;
+
+ if (UseVBO) {
+ glBindBufferARB_func(GL_ARRAY_BUFFER_ARB, VBO);
+ vertPtr = (void *) 0;
+ tex0Ptr = (void *) sizeof(VertCoords);
+ tex1Ptr = (void *) (sizeof(VertCoords) + sizeof(Tex0Coords));
+ }
+ else {
+ glBindBufferARB_func(GL_ARRAY_BUFFER_ARB, 0);
+ vertPtr = VertCoords;
+ tex0Ptr = Tex0Coords;
+ tex1Ptr = Tex1Coords;
+ }
+
if (VertCoord_attr >= 0) {
glVertexAttribPointer_func(VertCoord_attr, 2, GL_FLOAT, GL_FALSE,
- 0, VertCoords);
+ 0, vertPtr);
glEnableVertexAttribArray_func(VertCoord_attr);
}
else {
- glVertexPointer(2, GL_FLOAT, 0, VertCoords);
+ glVertexPointer(2, GL_FLOAT, 0, vertPtr);
glEnable(GL_VERTEX_ARRAY);
}
glVertexAttribPointer_func(TexCoord0_attr, 2, GL_FLOAT, GL_FALSE,
- 0, Tex0Coords);
+ 0, tex0Ptr);
glEnableVertexAttribArray_func(TexCoord0_attr);
glVertexAttribPointer_func(TexCoord1_attr, 2, GL_FLOAT, GL_FALSE,
- 0, Tex1Coords);
+ 0, tex1Ptr);
glEnableVertexAttribArray_func(TexCoord1_attr);
glDrawArrays(GL_TRIANGLE_FAN, 0, 4);
+
+ glBindBufferARB_func(GL_ARRAY_BUFFER_ARB, 0);
}
@@ -163,6 +218,10 @@ key(unsigned char k, int x, int y)
UseArrays = !UseArrays;
printf("Arrays: %d\n", UseArrays);
break;
+ case 'v':
+ UseVBO = !UseVBO;
+ printf("Use VBO: %d\n", UseVBO);
+ break;
case ' ':
Anim = !Anim;
if (Anim)
@@ -271,9 +330,24 @@ CreateProgram(const char *vertProgFile, const char *fragProgFile,
InitUniforms(program, uniforms);
+ VertCoord_attr = glGetAttribLocation_func(program, "VertCoord");
+ if (VertCoord_attr > 0) {
+ /* We want the VertCoord attrib to have position zero so that
+ * the call to glVertexAttrib(0, xyz) triggers vertex processing.
+ * Otherwise, if TexCoord0 or TexCoord1 gets position 0 we'd have
+ * to set that attribute last (which is a PITA to manage).
+ */
+ glBindAttribLocation_func(program, 0, "VertCoord");
+ /* re-link */
+ glLinkProgram_func(program);
+ /* VertCoord_attr should be zero now */
+ VertCoord_attr = glGetAttribLocation_func(program, "VertCoord");
+ assert(VertCoord_attr == 0);
+ }
+
TexCoord0_attr = glGetAttribLocation_func(program, "TexCoord0");
TexCoord1_attr = glGetAttribLocation_func(program, "TexCoord1");
- VertCoord_attr = glGetAttribLocation_func(program, "VertCoord");
+
printf("TexCoord0_attr = %d\n", TexCoord0_attr);
printf("TexCoord1_attr = %d\n", TexCoord1_attr);
printf("VertCoord_attr = %d\n", VertCoord_attr);
@@ -299,12 +373,19 @@ InitGL(void)
/*exit(1);*/
}
printf("GL_RENDERER = %s\n",(const char *) glGetString(GL_RENDERER));
-
+ printf("Usage:\n");
+ printf(" a - toggle arrays vs. immediate mode rendering\n");
+ printf(" v - toggle VBO usage for array rendering\n");
+ printf(" z/Z - change viewing distance\n");
+ printf(" SPACE - toggle animation\n");
+ printf(" Esc - exit\n");
GetExtensionFuncs();
InitTextures();
InitPrograms();
+ SetupVertexBuffer();
+
glEnable(GL_DEPTH_TEST);
glClearColor(.6, .6, .9, 0);