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Reviewed rlReadTexturePixels() for OpenGL ES 2.0

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Now it should work... but this behaviour could be driver dependant...
This commit is contained in:
Ray 2018-12-18 18:20:20 +01:00
parent 2f56119568
commit 39c05e30d0
1 changed files with 16 additions and 45 deletions
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61
src/rlgl.h
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@ -2637,8 +2637,6 @@ unsigned char *rlReadScreenPixels(int width, int height)
}
// Read texture pixel data
// NOTE: glGetTexImage() is not available on OpenGL ES 2.0
// Texture2D width and height are required on OpenGL ES 2.0. There is no way to get it from texture id.
void *rlReadTexturePixels(Texture2D texture)
{
void *pixels = NULL;
@ -2647,11 +2645,11 @@ void *rlReadTexturePixels(Texture2D texture)
glBindTexture(GL_TEXTURE_2D, texture.id);
// NOTE: Using texture.id, we can retrieve some texture info (but not on OpenGL ES 2.0)
// Possible texture info: GL_TEXTURE_RED_SIZE, GL_TEXTURE_GREEN_SIZE, GL_TEXTURE_BLUE_SIZE, GL_TEXTURE_ALPHA_SIZE
//int width, height, format;
//glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_WIDTH, &width);
//glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_HEIGHT, &height);
//glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_INTERNAL_FORMAT, &format);
// Other texture info: GL_TEXTURE_RED_SIZE, GL_TEXTURE_GREEN_SIZE, GL_TEXTURE_BLUE_SIZE, GL_TEXTURE_ALPHA_SIZE
// NOTE: Each row written to or read from by OpenGL pixel operations like glGetTexImage are aligned to a 4 byte boundary by default, which may add some padding.
// Use glPixelStorei to modify padding with the GL_[UN]PACK_ALIGNMENT setting.
@ -2674,66 +2672,39 @@ void *rlReadTexturePixels(Texture2D texture)
#endif
#if defined(GRAPHICS_API_OPENGL_ES2)
RenderTexture2D fbo = rlLoadRenderTexture(texture.width, texture.height);
// NOTE: Two possible Options:
// glGetTexImage() is not available on OpenGL ES 2.0
// Texture2D width and height are required on OpenGL ES 2.0. There is no way to get it from texture id.
// Two possible Options:
// 1 - Bind texture to color fbo attachment and glReadPixels()
// 2 - Create an fbo, activate it, render quad with texture, glReadPixels()
#define GET_TEXTURE_FBO_OPTION_1 // It works
#if defined(GET_TEXTURE_FBO_OPTION_1)
// We are using Option 1, just need to care for texture format on retrieval
// NOTE: This behaviour could be conditioned by graphic driver...
RenderTexture2D fbo = rlLoadRenderTexture(texture.width, texture.height);
glBindFramebuffer(GL_FRAMEBUFFER, fbo.id);
glBindTexture(GL_TEXTURE_2D, 0);
// Attach our texture to FBO -> Texture must be RGBA
// Attach our texture to FBO
// NOTE: Previoust attached texture is automatically detached
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture.id, 0);
pixels = (unsigned char *)malloc(texture.width*texture.height*4*sizeof(unsigned char));
// Allocate enough memory to read back our texture data
pixels = (unsigned char *)malloc(GetPixelDataSize(texture.width, texture.height, texture.format));
// Get OpenGL internal formats and data type from our texture format
unsigned int glInternalFormat, glFormat, glType;
rlGetGlTextureFormats(texture.format, &glInternalFormat, &glFormat, &glType);
// NOTE: We read data as RGBA because FBO texture is configured as RGBA, despite binding a RGB texture...
glReadPixels(0, 0, texture.width, texture.height, GL_RGBA, GL_UNSIGNED_BYTE, pixels);
glReadPixels(0, 0, texture.width, texture.height, glFormat, glType, pixels);
// Re-attach internal FBO color texture before deleting it
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, fbo.texture.id, 0);
glBindFramebuffer(GL_FRAMEBUFFER, 0);
#elif defined(GET_TEXTURE_FBO_OPTION_2)
// Render texture to fbo
glBindFramebuffer(GL_FRAMEBUFFER, fbo.id);
glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
glClearDepthf(1.0f);
//glDisable(GL_TEXTURE_2D);
glEnable(GL_DEPTH_TEST);
//glDisable(GL_BLEND);
glViewport(0, 0, texture.width, texture.height);
rlOrtho(0.0, texture.width, texture.height, 0.0, 0.0, 1.0);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glUseProgram(GetShaderDefault().id);
glBindTexture(GL_TEXTURE_2D, texture.id);
GenDrawQuad();
glBindTexture(GL_TEXTURE_2D, 0);
glUseProgram(0);
pixels = (unsigned char *)malloc(texture.width*texture.height*4*sizeof(unsigned char));
glReadPixels(0, 0, texture.width, texture.height, GL_RGBA, GL_UNSIGNED_BYTE, pixels);
// Bind framebuffer 0, which means render to back buffer
glBindFramebuffer(GL_FRAMEBUFFER, 0);
// Reset viewport dimensions to default
glViewport(0, 0, screenWidth, screenHeight);
#endif // GET_TEXTURE_FBO_OPTION
// Clean up temporal fbo
rlDeleteRenderTextures(fbo);
#endif
return pixels;