1 files changed, 69 insertions, 2 deletions

diff --git a/progs/glsl/multitex.c b/progs/glsl/multitex.c
index 913f73be171..5e971716add 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;
 
@@ -76,17 +78,68 @@ static const GLfloat VertCoords[4][2] = {
 };
 
 
+
+static void
+SetupVertexBuffer(void)
+{
+   glGenBuffersARB(1, &VBO);
+   glBindBufferARB(GL_ARRAY_BUFFER_ARB, VBO);
+
+   glBufferDataARB(GL_ARRAY_BUFFER_ARB,
+                        sizeof(VertCoords) +
+                        sizeof(Tex0Coords) +
+                        sizeof(Tex1Coords),
+                        NULL,
+                        GL_STATIC_DRAW_ARB);
+
+   /* non-interleaved vertex arrays */
+
+   glBufferSubDataARB(GL_ARRAY_BUFFER_ARB,
+                           0,                   /* offset */
+                           sizeof(VertCoords),  /* size */
+                           VertCoords);         /* data */
+
+   glBufferSubDataARB(GL_ARRAY_BUFFER_ARB,
+                           sizeof(VertCoords),  /* offset */
+                           sizeof(Tex0Coords),  /* size */
+                           Tex0Coords);         /* data */
+
+   glBufferSubDataARB(GL_ARRAY_BUFFER_ARB,
+                           sizeof(VertCoords) +
+                           sizeof(Tex0Coords),  /* offset */
+                           sizeof(Tex1Coords),  /* size */
+                           Tex1Coords);         /* data */
+
+   glBindBufferARB(GL_ARRAY_BUFFER_ARB, 0);
+}
+
+
 static void
 DrawPolygonArray(void)
 {
+   void *vertPtr, *tex0Ptr, *tex1Ptr;
+
+   if (UseVBO) {
+      glBindBufferARB(GL_ARRAY_BUFFER_ARB, VBO);
+      vertPtr = (void *) 0;
+      tex0Ptr = (void *) sizeof(VertCoords);
+      tex1Ptr = (void *) (sizeof(VertCoords) + sizeof(Tex0Coords));
+   }
+   else {
+      glBindBufferARB(GL_ARRAY_BUFFER_ARB, 0);
+      vertPtr = VertCoords;
+      tex0Ptr = Tex0Coords;
+      tex1Ptr = Tex1Coords;
+   }
+
    if (VertCoord_attr >= 0) {
       glVertexAttribPointer(VertCoord_attr, 2, GL_FLOAT, GL_FALSE,
                                  0, VertCoords);
       glEnableVertexAttribArray(VertCoord_attr);
    }
    else {
-      glVertexPointer(2, GL_FLOAT, 0, VertCoords);
-      glEnable(GL_VERTEX_ARRAY);
+      glVertexPointer(2, GL_FLOAT, 0, vertPtr);
+      glEnableClientState(GL_VERTEX_ARRAY);
    }
 
    glVertexAttribPointer(TexCoord0_attr, 2, GL_FLOAT, GL_FALSE,
@@ -98,6 +151,8 @@ DrawPolygonArray(void)
    glEnableVertexAttribArray(TexCoord1_attr);
 
    glDrawArrays(GL_TRIANGLE_FAN, 0, 4);
+
+   glBindBufferARB(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)
@@ -314,10 +373,18 @@ 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");
 
    InitTextures();
    InitPrograms();
 
+   SetupVertexBuffer();
+
    glEnable(GL_DEPTH_TEST);
 
    glClearColor(.6, .6, .9, 0);