Added test for passing two separate arrays of attributes, each

with different stride values but both tightly packed. The test case
test both passing explicit and implicit stride (0 means
"tightly packed").

3 files changed, 155 insertions, 0 deletions

diff --git a/tests/gl_stride.c b/tests/gl_stride.c
new file mode 100644
index 00000000..c254ad5a
--- /dev/null
+++ b/tests/gl_stride.c
@@ -0,0 +1,152 @@
+/*******************************************************************
+ *                                                                 *
+ *                        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 0
+#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;
+    
+    Vertex vertices[3] = {
+        {-1.0, 0.0},
+        { 0.0, 1.0},
+        { 1.0, 0.0}
+    };
+    
+    Color colors[3] = {
+        {0xFF, 0x00, 0x00, 0xFF},
+        {0x00, 0xFF, 0x00, 0xFF},
+        {0x00, 0x00, 0xFF, 0xFF}
+    };
+    
+    Vertex vertices2[3] = {
+        {-1.0,  0.0},
+        { 1.0,  0.0},
+        { 0.0, -1.0}
+    };
+    
+    Color colors2[3] = {
+        {0xFF, 0x00, 0x00, 0xFF},
+        {0x00, 0x00, 0xFF, 0xFF},
+        {0x00, 0xFF, 0x00, 0xFF}
+    };
+    
+    // DRAW
+    
+    // Clear the screen before drawing
+    glClear( GL_COLOR_BUFFER_BIT );
+    
+    // This test ensures that we can use two separate arrays in memory for different
+    // attributes, and that they each can have different stride.
+    // The first test shows implicit striding (the zero indicates tightly packed)
+    // The second test shows explicit striding where the stride is passed in
+    //   even though it also is tightly packed
+    
+    glEnableClientState(GL_VERTEX_ARRAY);
+    glEnableClientState(GL_COLOR_ARRAY);
+
+    // TEST 1
+    
+    glVertexPointer(2, GL_FLOAT, 0, vertices);
+    glColorPointer(4, GL_UNSIGNED_BYTE, 0, colors);
+    glDrawArrays(GL_TRIANGLE_STRIP, 0, 3);
+    
+    // TEST 2
+    
+    glVertexPointer(2, GL_FLOAT, 8, vertices2);
+    glColorPointer(4, GL_UNSIGNED_BYTE, 4, colors2);
+    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_stride.png b/tests/gl_stride.png
new file mode 100644
index 00000000..db1bc751
--- /dev/null
+++ b/tests/gl_stride.png
diff --git a/tests/runner.py b/tests/runner.py
index 8786d4f6..229b776c 100755
--- a/tests/runner.py
+++ b/tests/runner.py
@@ -11587,6 +11587,9 @@ elif 'browser' in str(sys.argv):
     def test_gl_renderers(self):
       self.btest('gl_renderers.c', reference='gl_renderers.png', args=['-s', 'GL_UNSAFE_OPTS=0'])
 
+    def test_gl_stride(self):
+      self.btest('gl_stride.c', reference='gl_stride.png', args=['-s', 'GL_UNSAFE_OPTS=0'])
+
     def test_matrix_identity(self):
       self.btest('gl_matrix_identity.c', expected=['-1882984448', '460451840'])