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Diffstat (limited to 'tests/gl_vertex_buffer_pre.c')
| -rw-r--r-- | tests/gl_vertex_buffer_pre.c | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/tests/gl_vertex_buffer_pre.c b/tests/gl_vertex_buffer_pre.c new file mode 100644 index 00000000..84b76569 --- /dev/null +++ b/tests/gl_vertex_buffer_pre.c @@ -0,0 +1,177 @@ +/******************************************************************* + * * + * 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> + +#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 Color { + GLubyte r; + GLubyte g; + GLubyte b; + GLubyte a; + } Color; + + typedef struct Vertex { + GLfloat x; + GLfloat y; + Color color; + } Vertex; + + Vertex vertices[18] = { + {-1.00, 0.0, {0xFF, 0x00, 0xFF, 0xFF}}, + {-1.00, 1.0, {0xFF, 0xFF, 0x00, 0xFF}}, + {-0.75, 0.0, {0xFF, 0x00, 0x00, 0xFF}}, + {-0.75, 1.0, {0xFF, 0xFF, 0xFF, 0xFF}}, + {-0.50, 0.0, {0xFF, 0x00, 0x00, 0xFF}}, + {-0.50, 1.0, {0xFF, 0xFF, 0x00, 0xFF}}, + {-0.25, 0.0, {0xFF, 0x00, 0xFF, 0xFF}}, + {-0.25, 1.0, {0xFF, 0xFF, 0x00, 0xFF}}, + {-0.00, 0.0, {0xFF, 0x00, 0x00, 0xFF}}, + {-0.00, 1.0, {0xFF, 0xFF, 0xFF, 0xFF}}, + { 0.25, 0.0, {0xFF, 0x00, 0x00, 0xFF}}, + { 0.25, 1.0, {0xFF, 0xFF, 0x00, 0xFF}}, + { 0.50, 0.0, {0xFF, 0x00, 0xFF, 0xFF}}, + { 0.50, 1.0, {0xFF, 0xFF, 0x00, 0xFF}}, + { 0.75, 0.0, {0xFF, 0x00, 0x00, 0xFF}}, + { 0.75, 1.0, {0xFF, 0xFF, 0xFF, 0xFF}}, + { 1.00, 0.0, {0xFF, 0x00, 0x00, 0xFF}}, + { 1.00, 1.0, {0xFF, 0xFF, 0x00, 0xFF}} + }; + + Vertex vertices2[18] = { + {-1.00, -1.0, {0xFF, 0x00, 0xFF, 0xFF}}, + {-1.00, 0.0, {0xFF, 0xFF, 0x00, 0xFF}}, + {-0.75, -1.0, {0xFF, 0x00, 0x00, 0xFF}}, + {-0.75, 0.0, {0xFF, 0xFF, 0xFF, 0xFF}}, + {-0.50, -1.0, {0xFF, 0x00, 0x00, 0xFF}}, + {-0.50, 0.0, {0xFF, 0xFF, 0x00, 0xFF}}, + {-0.25, -1.0, {0xFF, 0x00, 0xFF, 0xFF}}, + {-0.25, 0.0, {0xFF, 0xFF, 0x00, 0xFF}}, + {-0.00, -1.0, {0xFF, 0x00, 0x00, 0xFF}}, + {-0.00, 0.0, {0xFF, 0xFF, 0xFF, 0xFF}}, + { 0.25, -1.0, {0xFF, 0x00, 0x00, 0xFF}}, + { 0.25, 0.0, {0xFF, 0xFF, 0x00, 0xFF}}, + { 0.50, -1.0, {0xFF, 0x00, 0xFF, 0xFF}}, + { 0.50, 0.0, {0xFF, 0xFF, 0x00, 0xFF}}, + { 0.75, -1.0, {0xFF, 0x00, 0x00, 0xFF}}, + { 0.75, 0.0, {0xFF, 0xFF, 0xFF, 0xFF}}, + { 1.00, -1.0, {0xFF, 0x00, 0x00, 0xFF}}, + { 1.00, 0.0, {0xFF, 0xFF, 0x00, 0xFF}} + }; + + // make a vertex buffer for the second set of vertices + GLuint vbo = 0; + glGenBuffers(1, &vbo); + + + // bind to it + glBindBuffer(GL_ARRAY_BUFFER, vbo); + // send it to gl + glBufferData(GL_ARRAY_BUFFER, sizeof(vertices2), vertices2, GL_STATIC_DRAW); + + // unbind from it + glBindBuffer(GL_ARRAY_BUFFER, 0); + + + // 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. + + glEnableClientState(GL_VERTEX_ARRAY); + glEnableClientState(GL_COLOR_ARRAY); + + glVertexPointer(2, GL_FLOAT, sizeof(Vertex), vertices); + glColorPointer(4, GL_UNSIGNED_BYTE, sizeof(Vertex), &vertices[0].color); + glDrawArrays(GL_TRIANGLE_STRIP, 10, 3); + glDrawArrays(GL_TRIANGLE_STRIP, 0, 6); + + glBindBuffer(GL_ARRAY_BUFFER, 0); + + 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; +} |