Added a test that creates two vertex buffers with different strides and pointers and

tests that the renderer can handle the changing strides and pointers.
The resulting image should be a fat diamond with colored vertices as seen
in the included image.

3 files changed, 193 insertions, 0 deletions

diff --git a/tests/gl_renderers.c b/tests/gl_renderers.c
new file mode 100644
index 00000000..acf400ff
--- /dev/null
+++ b/tests/gl_renderers.c
@@ -0,0 +1,189 @@
+/*******************************************************************
+ *                                                                 *
+ *                        Using SDL With OpenGL                    *
+ *                                                                 *
+ *                    Tutorial by Kyle Foley (sdw)                 *
+ *                                                                 *
+ * http://gpwiki.org/index.php/SDL:Tutorials:Using_SDL_with_OpenGL *
+ *                                                                 *
+ *******************************************************************/
+
+/*
+THIS WORK, INCLUDING THE SOURCE CODE, DOCUMENTATION
+AND RELATED MEDIA AND DATA, IS PLACED INTO THE PUBLIC DOMAIN.
+
+THE ORIGINAL AUTHOR IS KYLE FOLEY.
+
+THIS SOFTWARE IS PROVIDED AS-IS WITHOUT WARRANTY
+OF ANY KIND, NOT EVEN THE IMPLIED WARRANTY OF
+MERCHANTABILITY. THE AUTHOR OF THIS SOFTWARE,
+ASSUMES _NO_ RESPONSIBILITY FOR ANY CONSEQUENCE
+RESULTING FROM THE USE, MODIFICATION, OR
+REDISTRIBUTION OF THIS SOFTWARE.
+*/
+
+#if !EMSCRIPTEN
+#define USE_GLEW 1
+#endif
+
+#if USE_GLEW
+#include "GL/glew.h"
+#endif
+
+#include "SDL/SDL.h"
+#include "SDL/SDL_image.h"
+#if !USE_GLEW
+#include "SDL/SDL_opengl.h"
+#endif
+
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+
+int main(int argc, char *argv[])
+{
+    SDL_Surface *screen;
+
+    // Slightly different SDL initialization
+    if ( SDL_Init(SDL_INIT_VIDEO) != 0 ) {
+        printf("Unable to initialize SDL: %s\n", SDL_GetError());
+        return 1;
+    }
+
+    SDL_GL_SetAttribute( SDL_GL_DOUBLEBUFFER, 1 ); // *new*
+
+    screen = SDL_SetVideoMode( 640, 480, 16, SDL_OPENGL ); // *changed*
+    if ( !screen ) {
+        printf("Unable to set video mode: %s\n", SDL_GetError());
+        return 1;
+    }
+    
+    // Set the OpenGL state after creating the context with SDL_SetVideoMode
+
+    glClearColor( 0, 0, 0, 0 );
+    
+#if !EMSCRIPTEN
+    glEnable( GL_TEXTURE_2D ); // Need this to display a texture XXX unnecessary in OpenGL ES 2.0/WebGL
+#endif
+
+    glViewport( 0, 0, 640, 480 );
+    
+    glMatrixMode( GL_MODELVIEW );
+    glLoadIdentity();
+    
+    // Clear the screen before drawing
+    glClear( GL_COLOR_BUFFER_BIT );
+    
+    typedef struct Vertex {
+        GLfloat x;
+        GLfloat y;
+    } Vertex;
+    
+    typedef struct Color {
+        GLubyte r;
+        GLubyte g;
+        GLubyte b;
+        GLubyte a;
+    } Color;
+    
+    typedef struct Type1 {
+        Vertex location;
+        Color  color;
+    } Type1;
+    
+    typedef struct Type2 {
+        GLuint unused1;
+        Vertex location;
+        GLfloat unused2;
+        Color  color;
+    } Type2;
+    
+    Type1 first[3] = {
+        {{-1.0, 0.0}, {0xFF, 0x00, 0x00, 0xFF}},
+        {{ 0.0, 1.0}, {0x00, 0xFF, 0x00, 0xFF}},
+        {{ 1.0, 0.0}, {0x00, 0x00, 0xFF, 0xFF}}
+    };
+    
+    Type2 second[3] = {
+        {0.0, {-1.0,  0.0}, 0.0, {0xFF, 0x00, 0x00, 0xFF}},
+        {0.0, { 1.0,  0.0}, 0.0, {0x00, 0x00, 0xFF, 0xFF}},
+        {0.0, { 0.0, -1.0}, 0.0, {0x00, 0xFF, 0x00, 0xFF}}};
+    
+    // make two vbo objects
+    GLuint vbo[2];
+    glGenBuffers(2, &vbo[0]);
+    
+    // load the first into the context
+    glBindBuffer(GL_ARRAY_BUFFER, vbo[0]);
+    
+    // allocate enough space for 100 vertices
+    glBufferData(GL_ARRAY_BUFFER, sizeof(Type1)*100, NULL, GL_DYNAMIC_DRAW);
+    
+    // load the second into the context
+    glBindBuffer(GL_ARRAY_BUFFER, vbo[1]);
+    
+    // allocate enough space for 100 vertices
+    glBufferData(GL_ARRAY_BUFFER, sizeof(Type2)*100, NULL, GL_DYNAMIC_DRAW);
+    
+    // DRAW
+    
+    // Clear the screen before drawing
+    glClear( GL_COLOR_BUFFER_BIT );
+    
+    glEnableClientState(GL_VERTEX_ARRAY);
+    glEnableClientState(GL_COLOR_ARRAY);
+    
+    // FIRST
+    // load the first into the context
+    glBindBuffer(GL_ARRAY_BUFFER, vbo[0]);
+    
+    // Load actual data in
+    glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(Type1)*3, &first[0]);
+    
+    // point to the buffer's location data
+    glVertexPointer(2, GL_FLOAT, sizeof(Type1), NULL);
+    
+    GLbyte * pointer = (GLbyte*)(((GLbyte*)&first[0].color) - ((GLbyte*)&first[0].location));
+
+    printf("location = %p\n", pointer);
+    // point to the buffer's color data
+    glColorPointer(4, GL_UNSIGNED_BYTE, sizeof(Type1), pointer);
+    
+    glDrawArrays(GL_TRIANGLE_STRIP, 0, 3);
+    
+    // SECOND
+    
+    // load the first into the context
+    glBindBuffer(GL_ARRAY_BUFFER, vbo[1]);
+    
+    // Load actual data in
+    glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(Type2)*3, &second[0]);
+    
+    pointer = (GLbyte*)((GLbyte*)&second[0].location - (GLbyte*)&second[0].unused1);
+    
+    // point to the buffer's location data
+    printf("location = %p\n", pointer);
+    glVertexPointer(2, GL_FLOAT, sizeof(Type2), pointer);
+    
+    pointer = (GLbyte*)((GLbyte*)&second[0].color - (GLbyte*)&second[0].unused1);
+    
+    // point to the buffer's location data
+    printf("location = %p\n", pointer);
+    glColorPointer(4, GL_UNSIGNED_BYTE, sizeof(Type2), pointer);
+    
+    glDrawArrays(GL_TRIANGLE_STRIP, 0, 3);
+    
+    glDisableClientState(GL_COLOR_ARRAY);
+    glDisableClientState(GL_VERTEX_ARRAY);
+
+    SDL_GL_SwapBuffers();
+    
+#if !EMSCRIPTEN
+    // Wait for 3 seconds to give us a chance to see the image
+    SDL_Delay(3000);
+#endif
+
+    SDL_Quit();
+    
+    return 0;
+}
diff --git a/tests/gl_renderers.png b/tests/gl_renderers.png
new file mode 100644
index 00000000..c3ec8f41
--- /dev/null
+++ b/tests/gl_renderers.png
diff --git a/tests/runner.py b/tests/runner.py
index 906375a5..edd2a4e9 100755
--- a/tests/runner.py
+++ b/tests/runner.py
@@ -11531,6 +11531,10 @@ elif 'browser' in str(sys.argv):
       shutil.copyfile(path_from_root('tests', 'screenshot.png'), os.path.join(self.get_dir(), 'screenshot.png'))
       self.btest('gl_ps_strides.c', reference='gl_ps_strides.png', args=['--preload-file', 'screenshot.png'])
 
+    def test_gl_renderers(self):
+      shutil.copyfile(path_from_root('tests', 'screenshot.png'), os.path.join(self.get_dir(), 'screenshot.png'))
+      self.btest('gl_renderers.c', reference='gl_renderers.png', args=['--preload-file', 'screenshot.png'])
+
     def test_matrix_identity(self):
       self.btest('gl_matrix_identity.c', expected=['-1882984448', '460451840'])