Index: third_party/gles_book_examples/Chapter_9/Simple_Texture2D/Simple_Texture2D.c |
=================================================================== |
--- third_party/gles_book_examples/Chapter_9/Simple_Texture2D/Simple_Texture2D.c (revision 35873) |
+++ third_party/gles_book_examples/Chapter_9/Simple_Texture2D/Simple_Texture2D.c (working copy) |
@@ -1,198 +0,0 @@ |
-// |
-// Book: OpenGL(R) ES 2.0 Programming Guide |
-// Authors: Aaftab Munshi, Dan Ginsburg, Dave Shreiner |
-// ISBN-10: 0321502795 |
-// ISBN-13: 9780321502797 |
-// Publisher: Addison-Wesley Professional |
-// URLs: http://safari.informit.com/9780321563835 |
-// http://www.opengles-book.com |
-// |
- |
-// Simple_Texture2D.c |
-// |
-// This is a simple example that draws a quad with a 2D |
-// texture image. The purpose of this example is to demonstrate |
-// the basics of 2D texturing |
-// |
-#include <stdlib.h> |
-#include "esUtil.h" |
- |
-typedef struct |
-{ |
- // Handle to a program object |
- GLuint programObject; |
- |
- // Attribute locations |
- GLint positionLoc; |
- GLint texCoordLoc; |
- |
- // Sampler location |
- GLint samplerLoc; |
- |
- // Texture handle |
- GLuint textureId; |
- |
-} UserData; |
- |
-/// |
-// Create a simple 2x2 texture image with four different colors |
-// |
-GLuint CreateSimpleTexture2D( ) |
-{ |
- // Texture object handle |
- GLuint textureId; |
- |
- // 2x2 Image, 3 bytes per pixel (R, G, B) |
- GLubyte pixels[4 * 3] = |
- { |
- 255, 0, 0, // Red |
- 0, 255, 0, // Green |
- 0, 0, 255, // Blue |
- 255, 255, 0 // Yellow |
- }; |
- |
- // Use tightly packed data |
- glPixelStorei ( GL_UNPACK_ALIGNMENT, 1 ); |
- |
- // Generate a texture object |
- glGenTextures ( 1, &textureId ); |
- |
- // Bind the texture object |
- glBindTexture ( GL_TEXTURE_2D, textureId ); |
- |
- // Load the texture |
- glTexImage2D ( GL_TEXTURE_2D, 0, GL_RGB, 2, 2, 0, GL_RGB, GL_UNSIGNED_BYTE, pixels ); |
- |
- // Set the filtering mode |
- glTexParameteri ( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST ); |
- glTexParameteri ( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST ); |
- |
- return textureId; |
- |
-} |
- |
- |
-/// |
-// Initialize the shader and program object |
-// |
-int Init ( ESContext *esContext ) |
-{ |
- UserData *userData = esContext->userData; |
- GLbyte vShaderStr[] = |
- "attribute vec4 a_position; \n" |
- "attribute vec2 a_texCoord; \n" |
- "varying vec2 v_texCoord; \n" |
- "void main() \n" |
- "{ \n" |
- " gl_Position = a_position; \n" |
- " v_texCoord = a_texCoord; \n" |
- "} \n"; |
- |
- GLbyte fShaderStr[] = |
- "precision mediump float; \n" |
- "varying vec2 v_texCoord; \n" |
- "uniform sampler2D s_texture; \n" |
- "void main() \n" |
- "{ \n" |
- " gl_FragColor = texture2D( s_texture, v_texCoord );\n" |
- "} \n"; |
- |
- // Load the shaders and get a linked program object |
- userData->programObject = esLoadProgram ( vShaderStr, fShaderStr ); |
- |
- // Get the attribute locations |
- userData->positionLoc = glGetAttribLocation ( userData->programObject, "a_position" ); |
- userData->texCoordLoc = glGetAttribLocation ( userData->programObject, "a_texCoord" ); |
- |
- // Get the sampler location |
- userData->samplerLoc = glGetUniformLocation ( userData->programObject, "s_texture" ); |
- |
- // Load the texture |
- userData->textureId = CreateSimpleTexture2D (); |
- |
- glClearColor ( 0.0f, 0.0f, 0.0f, 0.0f ); |
- return TRUE; |
-} |
- |
-/// |
-// Draw a triangle using the shader pair created in Init() |
-// |
-void Draw ( ESContext *esContext ) |
-{ |
- UserData *userData = esContext->userData; |
- GLfloat vVertices[] = { -0.5f, 0.5f, 0.0f, // Position 0 |
- 0.0f, 0.0f, // TexCoord 0 |
- -0.5f, -0.5f, 0.0f, // Position 1 |
- 0.0f, 1.0f, // TexCoord 1 |
- 0.5f, -0.5f, 0.0f, // Position 2 |
- 1.0f, 1.0f, // TexCoord 2 |
- 0.5f, 0.5f, 0.0f, // Position 3 |
- 1.0f, 0.0f // TexCoord 3 |
- }; |
- GLushort indices[] = { 0, 1, 2, 0, 2, 3 }; |
- |
- // Set the viewport |
- glViewport ( 0, 0, esContext->width, esContext->height ); |
- |
- // Clear the color buffer |
- glClear ( GL_COLOR_BUFFER_BIT ); |
- |
- // Use the program object |
- glUseProgram ( userData->programObject ); |
- |
- // Load the vertex position |
- glVertexAttribPointer ( userData->positionLoc, 3, GL_FLOAT, |
- GL_FALSE, 5 * sizeof(GLfloat), vVertices ); |
- // Load the texture coordinate |
- glVertexAttribPointer ( userData->texCoordLoc, 2, GL_FLOAT, |
- GL_FALSE, 5 * sizeof(GLfloat), &vVertices[3] ); |
- |
- glEnableVertexAttribArray ( userData->positionLoc ); |
- glEnableVertexAttribArray ( userData->texCoordLoc ); |
- |
- // Bind the texture |
- glActiveTexture ( GL_TEXTURE0 ); |
- glBindTexture ( GL_TEXTURE_2D, userData->textureId ); |
- |
- // Set the sampler texture unit to 0 |
- glUniform1i ( userData->samplerLoc, 0 ); |
- |
- glDrawElements ( GL_TRIANGLES, 6, GL_UNSIGNED_SHORT, indices ); |
- |
- eglSwapBuffers ( esContext->eglDisplay, esContext->eglSurface ); |
-} |
- |
-/// |
-// Cleanup |
-// |
-void ShutDown ( ESContext *esContext ) |
-{ |
- UserData *userData = esContext->userData; |
- |
- // Delete texture object |
- glDeleteTextures ( 1, &userData->textureId ); |
- |
- // Delete program object |
- glDeleteProgram ( userData->programObject ); |
-} |
- |
- |
-int main ( int argc, char *argv[] ) |
-{ |
- ESContext esContext; |
- UserData userData; |
- |
- esInitContext ( &esContext ); |
- esContext.userData = &userData; |
- |
- esCreateWindow ( &esContext, "Simple Texture 2D", 320, 240, ES_WINDOW_RGB ); |
- |
- if ( !Init ( &esContext ) ) |
- return 0; |
- |
- esRegisterDrawFunc ( &esContext, Draw ); |
- |
- esMainLoop ( &esContext ); |
- |
- ShutDown ( &esContext ); |
-} |