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Added texture retrieval support on OpenGL ES 2.0

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Updated functions:
Image GetTextureData(Texture2D texture);
void *rlglReadTexturePixels(Texture2D texture);
This commit is contained in:
Ray 2015-11-05 12:32:47 +01:00
parent 2fa7e00f16
commit 88e1fd9530
3 changed files with 44 additions and 51 deletions
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74
src/rlgl.c
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@ -1029,7 +1029,7 @@ void rlglInit(void)
else TraceLog(WARNING, "[EXTENSION] VAO extension not found, VAO usage not supported");
if (npotSupported) TraceLog(INFO, "[EXTENSION] NPOT textures extension detected, full NPOT textures supported");
else TraceLog(WARNING, "[EXTENSION] NPOT textures extension not found, NPOT textures support is limited (no-mipmaps, no-repeat");
else TraceLog(WARNING, "[EXTENSION] NPOT textures extension not found, NPOT textures support is limited (no-mipmaps, no-repeat)");
#endif
if (texCompDXTSupported) TraceLog(INFO, "[EXTENSION] DXT compressed textures supported");
@ -2051,8 +2051,6 @@ Model rlglLoadModel(VertexData mesh)
}
// Read screen pixel data (color buffer)
// ISSUE: Non pre-multiplied alpha when reading from backbuffer!
// TODO: Multiply alpha
unsigned char *rlglReadScreenPixels(int width, int height)
{
unsigned char *screenData = (unsigned char *)malloc(width*height*sizeof(unsigned char)*4);
@ -2082,28 +2080,30 @@ unsigned char *rlglReadScreenPixels(int width, int height)
}
// Read texture pixel data
// NOTE: Retrieving pixel data from GPU (glGetTexImage()) not supported on OpenGL ES 2.0
//void *rlglReadTexturePixels(Texture2D texture) // Required to know texture size! It could not be retrieved on OpenGL ES 2.0
void *rlglReadTexturePixels(unsigned int textureId, unsigned int format)
// 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 *rlglReadTexturePixels(Texture2D texture)
{
void *pixels = NULL;
#if defined(GRAPHICS_API_OPENGL_11) || defined(GRAPHICS_API_OPENGL_33)
int width, height;
glBindTexture(GL_TEXTURE_2D, textureId);
glBindTexture(GL_TEXTURE_2D, texture.id);
// NOTE: Using texture.id, we can retrieve some texture info (but not on OpenGL ES 2.0)
/*
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);
//GL_TEXTURE_RED_SIZE, GL_TEXTURE_GREEN_SIZE, GL_TEXTURE_BLUE_SIZE, GL_TEXTURE_ALPHA_SIZE
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
*/
int glFormat = 0, glType = 0;
unsigned int size = width*height;
unsigned int size = texture.width*texture.height;
// NOTE: GL_LUMINANCE and GL_LUMINANCE_ALPHA are removed since OpenGL 3.1
// Must be replaced by GL_RED and GL_RG on Core OpenGL 3.3 and data must be swizzled
// Must be replaced by GL_RED and GL_RG on Core OpenGL 3.3
switch (format)
{
@ -2111,27 +2111,15 @@ void *rlglReadTexturePixels(unsigned int textureId, unsigned int format)
case UNCOMPRESSED_GRAYSCALE: pixels = (unsigned char *)malloc(size); glFormat = GL_LUMINANCE; glType = GL_UNSIGNED_BYTE; break; // 8 bit per pixel (no alpha)
case UNCOMPRESSED_GRAY_ALPHA: pixels = (unsigned char *)malloc(size*2); glFormat = GL_LUMINANCE_ALPHA; glType = GL_UNSIGNED_BYTE; break; // 16 bpp (2 channels)
#elif defined(GRAPHICS_API_OPENGL_33)
case UNCOMPRESSED_GRAYSCALE: // 8 bit per pixel (no alpha)
{
pixels = (unsigned char *)malloc(size); glFormat = GL_RED; glType = GL_UNSIGNED_BYTE;
GLint swizzleMask[] = { GL_RED, GL_RED, GL_RED, GL_ONE };
glTexParameteriv(GL_TEXTURE_2D, GL_TEXTURE_SWIZZLE_RGBA, swizzleMask);
} break;
case UNCOMPRESSED_GRAY_ALPHA: // 16 bpp (2 channels)
{
pixels = (unsigned char *)malloc(size*2); glFormat = GL_RG; glType = GL_UNSIGNED_BYTE;
GLint swizzleMask[] = { GL_RED, GL_RED, GL_RED, GL_GREEN };
glTexParameteriv(GL_TEXTURE_2D, GL_TEXTURE_SWIZZLE_RGBA, swizzleMask);
} break;
case UNCOMPRESSED_GRAYSCALE: pixels = (unsigned char *)malloc(size); glFormat = GL_RED; glType = GL_UNSIGNED_BYTE; break;
case UNCOMPRESSED_GRAY_ALPHA: pixels = (unsigned char *)malloc(size*2); glFormat = GL_RG; glType = GL_UNSIGNED_BYTE; break;
#endif
case UNCOMPRESSED_R5G6B5: pixels = (unsigned short *)malloc(size); glFormat = GL_RGB; glType = GL_UNSIGNED_SHORT_5_6_5; break; // 16 bpp
case UNCOMPRESSED_R8G8B8: pixels = (unsigned char *)malloc(size*3); glFormat = GL_RGB; glType = GL_UNSIGNED_BYTE; break; // 24 bpp
case UNCOMPRESSED_R5G5B5A1: pixels = (unsigned short *)malloc(size); glFormat = GL_RGBA; glType = GL_UNSIGNED_SHORT_5_5_5_1; break; // 16 bpp (1 bit alpha)
case UNCOMPRESSED_R4G4B4A4: pixels = (unsigned short *)malloc(size); glFormat = GL_RGBA; glType = GL_UNSIGNED_SHORT_4_4_4_4; break; // 16 bpp (4 bit alpha)
case UNCOMPRESSED_R8G8B8A8: pixels = (unsigned char *)malloc(size*4); glFormat = GL_RGBA; glType = GL_UNSIGNED_BYTE; break; // 32 bpp
default: TraceLog(WARNING, "Texture format not suported"); break;
default: TraceLog(WARNING, "Texture data retrieval, format not suported"); break;
}
// 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.
@ -2146,34 +2134,36 @@ void *rlglReadTexturePixels(unsigned int textureId, unsigned int format)
#endif
#if defined(GRAPHICS_API_OPENGL_ES2)
// TODO: Look for some way to retrieve texture width and height from id -> NO WAY AVAILABLE
int width = 1024;
int height = 1024;
FBO fbo = rlglLoadFBO(width, height);
FBO fbo = rlglLoadFBO(texture.width, texture.height);
// NOTE: 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
#define GET_TEXTURE_FBO_OPTION_1 // It works
#if defined(GET_TEXTURE_FBO_OPTION_1)
glBindFramebuffer(GL_FRAMEBUFFER, fbo.id);
glBindTexture(GL_TEXTURE_2D, 0);
// Attach color texture and depth renderbuffer to FBO
// NOTE: texture must RGB
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, textureId, 0);
// Attach our texture to FBO -> Texture must be RGB
// NOTE: Previoust attached texture is automatically detached
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture.id, 0);
pixels = (unsigned char *)malloc(width*height*3*sizeof(unsigned char));
pixels = (unsigned char *)malloc(texture.width*texture.height*4*sizeof(unsigned char));
glReadPixels(0, 0, width, height, GL_RGB, GL_UNSIGNED_BYTE, pixels);
// NOTE: Despite FBO color texture is RGB, we read data as RGBA... reading as RGB doesn't work... o__O
glReadPixels(0, 0, texture.width, texture.height, GL_RGBA, GL_UNSIGNED_BYTE, pixels);
// Re-attach internal FBO color texture before deleting it
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, fbo.colorTextureId, 0);
glBindFramebuffer(GL_FRAMEBUFFER, 0);
#elif defined(GET_TEXTURE_FBO_OPTION_2)
// Render texture to fbo
glBindFramebuffer(GL_FRAMEBUFFER, fbo.id);
glClearColor(0.0, 0.0, 0.0, 0.0);
glClearDepthf(1.0f);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
@ -2194,12 +2184,14 @@ void *rlglReadTexturePixels(unsigned int textureId, unsigned int format)
DrawModel(quad, (Vector3){ 0, 0, 0 }, 1.0f, WHITE);
pixels = (unsigned char *)malloc(width*height*4*sizeof(unsigned char));
pixels = (unsigned char *)malloc(texture.width*texture.height*3*sizeof(unsigned char));
glReadPixels(0, 0, width, height, GL_RGBA, GL_UNSIGNED_BYTE, pixels);
glReadPixels(0, 0, texture.width, texture.height, GL_RGB, GL_UNSIGNED_BYTE, pixels);
// Bind framebuffer 0, which means render to back buffer
glBindFramebuffer(GL_FRAMEBUFFER, 0);
UnloadModel(quad);
#endif // GET_TEXTURE_FBO_OPTION
// Clean up temporal fbo

6
src/rlgl.h
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@ -255,10 +255,10 @@ void rlglDrawPostpro(void); // Draw with postprocessing shad
Model rlglLoadModel(VertexData mesh); // Upload vertex data into GPU and provided VAO/VBO ids
void rlglDrawModel(Model model, Vector3 position, float rotationAngle, Vector3 rotationAxis, Vector3 scale, Color color, bool wires);
Vector3 rlglUnproject(Vector3 source, Matrix proj, Matrix view); // Get world coordinates from screen coordinates
Vector3 rlglUnproject(Vector3 source, Matrix proj, Matrix view); // Get world coordinates from screen coordinates
unsigned char *rlglReadScreenPixels(int width, int height); // Read screen pixel data (color buffer)
void *rlglReadTexturePixels(unsigned int textureId, unsigned int format); // Read texture pixel data
unsigned char *rlglReadScreenPixels(int width, int height); // Read screen pixel data (color buffer)
void *rlglReadTexturePixels(Texture2D texture); // Read texture pixel data
#if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_ES2)
void PrintProjectionMatrix(void); // DEBUG: Print projection matrix

15
src/textures.c
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@ -502,26 +502,27 @@ Image GetTextureData(Texture2D texture)
Image image;
image.data = NULL;
#if defined(GRAPHICS_API_OPENGL_ES2)
TraceLog(WARNING, "Texture data retrieval not supported on OpenGL ES 2.0");
#else
if (texture.format < 8)
{
image.data = rlglReadTexturePixels(texture.id, texture.format);
image.data = rlglReadTexturePixels(texture);
if (image.data != NULL)
{
image.width = texture.width;
image.height = texture.height;
image.format = texture.format;
image.mipmaps = 1;
#if defined(GRAPHICS_API_OPENGL_ES2)
// NOTE: Data retrieved on OpenGL ES 2.0 comes as RGB (from framebuffer)
image.format = UNCOMPRESSED_R8G8B8A8;
#else
image.format = texture.format;
#endif
TraceLog(INFO, "Texture pixel data obtained successfully");
}
else TraceLog(WARNING, "Texture pixel data could not be obtained");
}
else TraceLog(WARNING, "Compressed texture data could not be obtained");
#endif
return image;
}