/*

Simple DirectMedia Layer

Copyright (C) 1997-2013 Sam Lantinga <slouken@libsdl.org>

This software is provided 'as-is', without any express or implied

warranty. In no event will the authors be held liable for any damages

arising from the use of this software.

Permission is granted to anyone to use this software for any purpose,

including commercial applications, and to alter it and redistribute it

freely, subject to the following restrictions:

1. The origin of this software must not be misrepresented; you must not

claim that you wrote the original software. If you use this software

in a product, an acknowledgment in the product documentation would be

appreciated but is not required.

2. Altered source versions must be plainly marked as such, and must not be

misrepresented as being the original software.

3. This notice may not be removed or altered from any source distribution.

*/

#include "SDL_config.h"

#if SDL_VIDEO_RENDER_OGL_ES2 && !SDL_RENDER_DISABLED

#include "SDL_hints.h"

#include "SDL_opengles2.h"

#include "../SDL_sysrender.h"

#include "SDL_shaders_gles2.h"

/* Used to re-create the window with OpenGL ES capability */

extern int SDL_RecreateWindow(SDL_Window * window, Uint32 flags);

/*************************************************************************************************

* Bootstrap data *

*************************************************************************************************/

static SDL_Renderer *GLES2_CreateRenderer(SDL_Window *window, Uint32 flags);

SDL_RenderDriver GLES2_RenderDriver = {

GLES2_CreateRenderer,

{

"opengles2",

(SDL_RENDERER_ACCELERATED | SDL_RENDERER_PRESENTVSYNC | SDL_RENDERER_TARGETTEXTURE),

4,

{SDL_PIXELFORMAT_ABGR8888,

SDL_PIXELFORMAT_ARGB8888,

SDL_PIXELFORMAT_RGB888,

SDL_PIXELFORMAT_BGR888},

0,

0

}

};

/*************************************************************************************************

* Context structures *

*************************************************************************************************/

typedef struct GLES2_FBOList GLES2_FBOList;

struct GLES2_FBOList

{

Uint32 w, h;

GLuint FBO;

GLES2_FBOList *next;

};

typedef struct GLES2_TextureData

{

GLenum texture;

GLenum texture_type;

GLenum pixel_format;

GLenum pixel_type;

void *pixel_data;

size_t pitch;

GLES2_FBOList *fbo;

} GLES2_TextureData;

typedef struct GLES2_ShaderCacheEntry

{

GLuint id;

GLES2_ShaderType type;

const GLES2_ShaderInstance *instance;

int references;

struct GLES2_ShaderCacheEntry *prev;

struct GLES2_ShaderCacheEntry *next;

} GLES2_ShaderCacheEntry;

typedef struct GLES2_ShaderCache

{

int count;

GLES2_ShaderCacheEntry *head;

} GLES2_ShaderCache;

typedef struct GLES2_ProgramCacheEntry

{

GLuint id;

SDL_BlendMode blend_mode;

GLES2_ShaderCacheEntry *vertex_shader;

GLES2_ShaderCacheEntry *fragment_shader;

GLuint uniform_locations[16];

struct GLES2_ProgramCacheEntry *prev;

struct GLES2_ProgramCacheEntry *next;

} GLES2_ProgramCacheEntry;

typedef struct GLES2_ProgramCache

{

int count;

GLES2_ProgramCacheEntry *head;

GLES2_ProgramCacheEntry *tail;

} GLES2_ProgramCache;

typedef enum

{

GLES2_ATTRIBUTE_POSITION = 0,

GLES2_ATTRIBUTE_TEXCOORD = 1,

GLES2_ATTRIBUTE_ANGLE = 2,

GLES2_ATTRIBUTE_CENTER = 3,

} GLES2_Attribute;

typedef enum

{

GLES2_UNIFORM_PROJECTION,

GLES2_UNIFORM_TEXTURE,

GLES2_UNIFORM_MODULATION,

GLES2_UNIFORM_COLOR,

GLES2_UNIFORM_COLORTABLE

} GLES2_Uniform;

typedef enum

{

GLES2_IMAGESOURCE_SOLID,

GLES2_IMAGESOURCE_TEXTURE_ABGR,

GLES2_IMAGESOURCE_TEXTURE_ARGB,

GLES2_IMAGESOURCE_TEXTURE_RGB,

GLES2_IMAGESOURCE_TEXTURE_BGR

} GLES2_ImageSource;

typedef struct GLES2_DriverContext

{

SDL_GLContext *context;

SDL_bool debug_enabled;

struct {

int blendMode;

SDL_bool tex_coords;

} current;

#define SDL_PROC(ret,func,params) ret (APIENTRY *func) params;

#include "SDL_gles2funcs.h"

#undef SDL_PROC

GLES2_FBOList *framebuffers;

GLuint window_framebuffer;

int shader_format_count;

GLenum *shader_formats;

GLES2_ShaderCache shader_cache;

GLES2_ProgramCache program_cache;

GLES2_ProgramCacheEntry *current_program;

} GLES2_DriverContext;

#define GLES2_MAX_CACHED_PROGRAMS 8

SDL_FORCE_INLINE const char*

GL_TranslateError (GLenum error)

{

#define GL_ERROR_TRANSLATE(e) case e: return #e;

switch (error) {

GL_ERROR_TRANSLATE(GL_INVALID_ENUM)

GL_ERROR_TRANSLATE(GL_INVALID_VALUE)

GL_ERROR_TRANSLATE(GL_INVALID_OPERATION)

GL_ERROR_TRANSLATE(GL_OUT_OF_MEMORY)

GL_ERROR_TRANSLATE(GL_NO_ERROR)

default:

return "UNKNOWN";

}

#undef GL_ERROR_TRANSLATE

}

SDL_FORCE_INLINE void

GL_ClearErrors(SDL_Renderer *renderer)

{

GLES2_DriverContext *data = (GLES2_DriverContext *) renderer->driverdata;

if (!data->debug_enabled)

{

return;

}

while (data->glGetError() != GL_NO_ERROR) {

continue;

}

}

SDL_FORCE_INLINE int

GL_CheckAllErrors (const char *prefix, SDL_Renderer *renderer, const char *file, int line, const char *function)

{

GLES2_DriverContext *data = (GLES2_DriverContext *) renderer->driverdata;

int ret = 0;

if (!data->debug_enabled)

{

return 0;

}

/* check gl errors (can return multiple errors) */

for (;;) {

GLenum error = data->glGetError();

if (error != GL_NO_ERROR) {

if (prefix == NULL || prefix[0] == '\0') {

prefix = "generic";

}

SDL_SetError("%s: %s (%d): %s %s (0x%X)", prefix, file, line, function, GL_TranslateError(error), error);

ret = -1;

} else {

break;

}

}

return ret;

}

#if 0

#define GL_CheckError(prefix, renderer)

#elif defined(_MSC_VER)

#define GL_CheckError(prefix, renderer) GL_CheckAllErrors(prefix, renderer, __FILE__, __LINE__, __FUNCTION__)

#else

#define GL_CheckError(prefix, renderer) GL_CheckAllErrors(prefix, renderer, __FILE__, __LINE__, __PRETTY_FUNCTION__)

#endif

/*************************************************************************************************

* Renderer state APIs *

*************************************************************************************************/

static int GLES2_ActivateRenderer(SDL_Renderer *renderer);

static void GLES2_WindowEvent(SDL_Renderer * renderer,

const SDL_WindowEvent *event);

static int GLES2_UpdateViewport(SDL_Renderer * renderer);

static void GLES2_DestroyRenderer(SDL_Renderer *renderer);

static int GLES2_SetOrthographicProjection(SDL_Renderer *renderer);

static SDL_GLContext SDL_CurrentContext = NULL;

static int GLES2_LoadFunctions(GLES2_DriverContext * data)

{

#if SDL_VIDEO_DRIVER_UIKIT

#define __SDL_NOGETPROCADDR__

#elif SDL_VIDEO_DRIVER_ANDROID

#define __SDL_NOGETPROCADDR__

#elif SDL_VIDEO_DRIVER_PANDORA

#define __SDL_NOGETPROCADDR__

#endif

#if defined __SDL_NOGETPROCADDR__

#define SDL_PROC(ret,func,params) data->func=func;

#else

#define SDL_PROC(ret,func,params) \

do { \

data->func = SDL_GL_GetProcAddress(#func); \

if ( ! data->func ) { \

return SDL_SetError("Couldn't load GLES2 function %s: %s\n", #func, SDL_GetError()); \

} \

} while ( 0 );

#endif /* _SDL_NOGETPROCADDR_ */

#include "SDL_gles2funcs.h"

#undef SDL_PROC

return 0;

}

GLES2_FBOList *

GLES2_GetFBO(GLES2_DriverContext *data, Uint32 w, Uint32 h)

{

GLES2_FBOList *result = data->framebuffers;

while ((result) && ((result->w != w) || (result->h != h)) )

{

result = result->next;

}

if (result == NULL)

{

result = SDL_malloc(sizeof(GLES2_FBOList));

result->w = w;

result->h = h;

data->glGenFramebuffers(1, &result->FBO);

result->next = data->framebuffers;

data->framebuffers = result;

}

return result;

}

static int

GLES2_ActivateRenderer(SDL_Renderer * renderer)

{

return -1;

}

GLES2_UpdateViewport(renderer);

}

GL_ClearErrors(renderer);

return 0;

}

static void

GLES2_WindowEvent(SDL_Renderer * renderer, const SDL_WindowEvent *event)

{

if (event->event == SDL_WINDOWEVENT_SIZE_CHANGED ||

event->event == SDL_WINDOWEVENT_SHOWN ||

event->event == SDL_WINDOWEVENT_HIDDEN) {

/* Rebind the context to the window area */

SDL_CurrentContext = NULL;

}

if (event->event == SDL_WINDOWEVENT_MINIMIZED) {

/* According to Apple documentation, we need to finish drawing NOW! */

}

}

static int

GLES2_UpdateViewport(SDL_Renderer * renderer)

{

/* We'll update the viewport after we rebind the context */

return 0;

}

renderer->viewport.w, renderer->viewport.h);

GLES2_SetOrthographicProjection(renderer);

}

}

static int

GLES2_UpdateClipRect(SDL_Renderer * renderer)

{

const SDL_Rect *rect = &renderer->clip_rect;

/* We'll update the clip rect after we rebind the context */

return 0;

}

if (!SDL_RectEmpty(rect)) {

data->glEnable(GL_SCISSOR_TEST);

data->glScissor(rect->x, renderer->viewport.h - rect->y - rect->h, rect->w, rect->h);

}

return 0;

}

static void

GLES2_DestroyRenderer(SDL_Renderer *renderer)

{

/* Deallocate everything */

GLES2_ActivateRenderer(renderer);

{

GLES2_ShaderCacheEntry *entry;

GLES2_ShaderCacheEntry *next;

while (entry)

{

next = entry->next;

SDL_free(entry);

entry = next;

}

}

{

GLES2_ProgramCacheEntry *entry;

GLES2_ProgramCacheEntry *next;

next = entry->next;

SDL_free(entry);

entry = next;

}

}

if (data->context) {

while (data->framebuffers) {

GLES2_FBOList *nextnode = data->framebuffers->next;

data->glDeleteFramebuffers(1, &data->framebuffers->FBO);

GL_CheckError("", renderer);

SDL_free(data->framebuffers);

data->framebuffers = nextnode;

SDL_free(data->shader_formats);

SDL_free(data);

}

SDL_free(renderer);

}

/*************************************************************************************************

* Texture APIs *

*************************************************************************************************/

static int GLES2_CreateTexture(SDL_Renderer *renderer, SDL_Texture *texture);

static int GLES2_UpdateTexture(SDL_Renderer *renderer, SDL_Texture *texture, const SDL_Rect *rect,

const void *pixels, int pitch);

static int GLES2_LockTexture(SDL_Renderer *renderer, SDL_Texture *texture, const SDL_Rect *rect,

void **pixels, int *pitch);

static void GLES2_UnlockTexture(SDL_Renderer *renderer, SDL_Texture *texture);

static int GLES2_SetRenderTarget(SDL_Renderer * renderer, SDL_Texture * texture);

static GLenum

GetScaleQuality(void)

{

const char *hint = SDL_GetHint(SDL_HINT_RENDER_SCALE_QUALITY);

if (!hint || *hint == '0' || SDL_strcasecmp(hint, "nearest") == 0) {

return GL_NEAREST;

} else {

return GL_LINEAR;

}

}

static int

GLES2_CreateTexture(SDL_Renderer *renderer, SDL_Texture *texture)

{

GLES2_DriverContext *renderdata = (GLES2_DriverContext *)renderer->driverdata;

GLES2_TextureData *data;

GLenum format;

GLenum type;

GLenum scaleMode;

GLES2_ActivateRenderer(renderer);

/* Determine the corresponding GLES texture format params */

switch (texture->format)

{

case SDL_PIXELFORMAT_ABGR8888:

case SDL_PIXELFORMAT_ARGB8888:

case SDL_PIXELFORMAT_BGR888:

case SDL_PIXELFORMAT_RGB888:

format = GL_RGBA;

type = GL_UNSIGNED_BYTE;

break;

default:

return SDL_SetError("Texture format not supported");

}

/* Allocate a texture struct */

data = (GLES2_TextureData *)SDL_calloc(1, sizeof(GLES2_TextureData));

if (!data) {

return SDL_OutOfMemory();

}

data->texture = 0;

data->texture_type = GL_TEXTURE_2D;

data->pixel_format = format;

data->pixel_type = type;

scaleMode = GetScaleQuality();

data->pitch = texture->w * SDL_BYTESPERPIXEL(texture->format);

data->pixel_data = SDL_calloc(1, data->pitch * texture->h);

if (!data->pixel_data) {

SDL_free(data);

return SDL_OutOfMemory();

}

}

/* Allocate the texture */

GL_CheckError("", renderer);

renderdata->glGenTextures(1, &data->texture);

if (GL_CheckError("glGenTexures()", renderer) < 0) {

return -1;

renderdata->glActiveTexture(GL_TEXTURE0);

renderdata->glBindTexture(data->texture_type, data->texture);

renderdata->glTexParameteri(data->texture_type, GL_TEXTURE_MIN_FILTER, scaleMode);

renderdata->glTexParameteri(data->texture_type, GL_TEXTURE_MAG_FILTER, scaleMode);

renderdata->glTexParameteri(data->texture_type, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);

renderdata->glTexParameteri(data->texture_type, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);

renderdata->glTexImage2D(data->texture_type, 0, format, texture->w, texture->h, 0, format, type, NULL);

if (GL_CheckError("glTexImage2D()", renderer) < 0) {

return -1;

}

if (texture->access == SDL_TEXTUREACCESS_TARGET) {

data->fbo = GLES2_GetFBO(renderer->driverdata, texture->w, texture->h);

} else {

data->fbo = NULL;

}

}

static int

GLES2_UpdateTexture(SDL_Renderer *renderer, SDL_Texture *texture, const SDL_Rect *rect,

const void *pixels, int pitch)

{

GLES2_TextureData *tdata = (GLES2_TextureData *)texture->driverdata;

Uint8 *blob = NULL;

Uint8 *src;

int srcPitch;

int y;

GLES2_ActivateRenderer(renderer);

/* Bail out if we're supposed to update an empty rectangle */

if (rect->w <= 0 || rect->h <= 0)

return 0;

/* Reformat the texture data into a tightly packed array */

srcPitch = rect->w * SDL_BYTESPERPIXEL(texture->format);

src = (Uint8 *)pixels;

if (pitch != srcPitch) {

blob = (Uint8 *)SDL_malloc(srcPitch * rect->h);

if (!blob) {

return SDL_OutOfMemory();

}

src = blob;

for (y = 0; y < rect->h; ++y)

{

SDL_memcpy(src, pixels, srcPitch);

src += srcPitch;

pixels = (Uint8 *)pixels + pitch;

}

src = blob;

}

/* Create a texture subimage with the supplied data */

data->glActiveTexture(GL_TEXTURE0);

data->glBindTexture(tdata->texture_type, tdata->texture);

data->glPixelStorei(GL_UNPACK_ALIGNMENT, 1);

data->glTexSubImage2D(tdata->texture_type,

0,

rect->x,

rect->y,

rect->w,

rect->h,

tdata->pixel_format,

tdata->pixel_type,

src);

return GL_CheckError("glTexSubImage2D()", renderer);

}

static int

GLES2_LockTexture(SDL_Renderer *renderer, SDL_Texture *texture, const SDL_Rect *rect,

void **pixels, int *pitch)

{

GLES2_TextureData *tdata = (GLES2_TextureData *)texture->driverdata;

/* Retrieve the buffer/pitch for the specified region */

*pixels = (Uint8 *)tdata->pixel_data +

(tdata->pitch * rect->y) +

(rect->x * SDL_BYTESPERPIXEL(texture->format));

*pitch = tdata->pitch;

return 0;

}

static void

GLES2_UnlockTexture(SDL_Renderer *renderer, SDL_Texture *texture)

{

GLES2_TextureData *tdata = (GLES2_TextureData *)texture->driverdata;

SDL_Rect rect;

/* We do whole texture updates, at least for now */

rect.x = 0;

rect.y = 0;

rect.w = texture->w;

rect.h = texture->h;

GLES2_UpdateTexture(renderer, texture, &rect, tdata->pixel_data, tdata->pitch);

}

static int

GLES2_SetRenderTarget(SDL_Renderer * renderer, SDL_Texture * texture)

{

GLES2_DriverContext *data = (GLES2_DriverContext *) renderer->driverdata;

GLES2_TextureData *texturedata = NULL;

GLenum status;

if (texture == NULL) {

data->glBindFramebuffer(GL_FRAMEBUFFER, data->window_framebuffer);

} else {

texturedata = (GLES2_TextureData *) texture->driverdata;

data->glBindFramebuffer(GL_FRAMEBUFFER, texturedata->fbo->FBO);

/* TODO: check if texture pixel format allows this operation */

data->glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, texturedata->texture_type, texturedata->texture, 0);

/* Check FBO status */

status = data->glCheckFramebufferStatus(GL_FRAMEBUFFER);

if (status != GL_FRAMEBUFFER_COMPLETE) {

return SDL_SetError("glFramebufferTexture2D() failed");

}

}

return 0;

}

static void

GLES2_DestroyTexture(SDL_Renderer *renderer, SDL_Texture *texture)

{

GLES2_DriverContext *data = (GLES2_DriverContext *)renderer->driverdata;

GLES2_TextureData *tdata = (GLES2_TextureData *)texture->driverdata;

GLES2_ActivateRenderer(renderer);

/* Destroy the texture */

if (tdata)

{

data->glDeleteTextures(1, &tdata->texture);

SDL_free(tdata->pixel_data);

SDL_free(tdata);

texture->driverdata = NULL;

}

}

/*************************************************************************************************

* Shader management functions *

*************************************************************************************************/

static GLES2_ShaderCacheEntry *GLES2_CacheShader(SDL_Renderer *renderer, GLES2_ShaderType type,

SDL_BlendMode blendMode);

static void GLES2_EvictShader(SDL_Renderer *renderer, GLES2_ShaderCacheEntry *entry);

static GLES2_ProgramCacheEntry *GLES2_CacheProgram(SDL_Renderer *renderer,

GLES2_ShaderCacheEntry *vertex,

GLES2_ShaderCacheEntry *fragment,

SDL_BlendMode blendMode);

static int GLES2_SelectProgram(SDL_Renderer *renderer, GLES2_ImageSource source,

SDL_BlendMode blendMode);

static GLES2_ProgramCacheEntry *

GLES2_CacheProgram(SDL_Renderer *renderer, GLES2_ShaderCacheEntry *vertex,

GLES2_ShaderCacheEntry *fragment, SDL_BlendMode blendMode)

{

GLES2_ProgramCacheEntry *entry;

GLES2_ShaderCacheEntry *shaderEntry;

GLint linkSuccessful;

/* Check if we've already cached this program */

while (entry)

{

if (entry->vertex_shader == vertex && entry->fragment_shader == fragment)

break;

entry = entry->next;

}

if (entry)

{

{

if (entry->next)

entry->next->prev = entry->prev;

if (entry->prev)

entry->prev->next = entry->next;

entry->prev = NULL;

entry->next = data->program_cache.head;

data->program_cache.head->prev = entry;

data->program_cache.head = entry;

}

return entry;

}

/* Create a program cache entry */

entry = (GLES2_ProgramCacheEntry *)SDL_calloc(1, sizeof(GLES2_ProgramCacheEntry));

if (!entry)

{

SDL_OutOfMemory();

return NULL;

}

entry->vertex_shader = vertex;

entry->fragment_shader = fragment;

entry->blend_mode = blendMode;

/* Create the program and link it */

entry->id = data->glCreateProgram();

data->glAttachShader(entry->id, vertex->id);

data->glAttachShader(entry->id, fragment->id);

data->glBindAttribLocation(entry->id, GLES2_ATTRIBUTE_POSITION, "a_position");

data->glBindAttribLocation(entry->id, GLES2_ATTRIBUTE_TEXCOORD, "a_texCoord");

data->glBindAttribLocation(entry->id, GLES2_ATTRIBUTE_ANGLE, "a_angle");

data->glBindAttribLocation(entry->id, GLES2_ATTRIBUTE_CENTER, "a_center");

data->glLinkProgram(entry->id);

data->glGetProgramiv(entry->id, GL_LINK_STATUS, &linkSuccessful);

SDL_free(entry);

SDL_SetError("Failed to link shader program");

return NULL;

}

/* Predetermine locations of uniform variables */

entry->uniform_locations[GLES2_UNIFORM_PROJECTION] =

/* Cache the linked program */

entry->next = data->program_cache.head;

data->program_cache.head->prev = entry;

}

else

{

data->program_cache.head = entry;

++data->program_cache.count;

/* Increment the refcount of the shaders we're using */

++vertex->references;

++fragment->references;

/* Evict the last entry from the cache if we exceed the limit */

if (--shaderEntry->references <= 0)

GLES2_EvictShader(renderer, shaderEntry);

if (--shaderEntry->references <= 0)

GLES2_EvictShader(renderer, shaderEntry);

data->glDeleteProgram(data->program_cache.tail->id);

data->program_cache.tail = data->program_cache.tail->prev;

SDL_free(data->program_cache.tail->next);

data->program_cache.tail->next = NULL;

--data->program_cache.count;

}

return entry;

}

static GLES2_ShaderCacheEntry *

GLES2_CacheShader(SDL_Renderer *renderer, GLES2_ShaderType type, SDL_BlendMode blendMode)

{

const GLES2_Shader *shader;

const GLES2_ShaderInstance *instance = NULL;

GLES2_ShaderCacheEntry *entry = NULL;

GLint compileSuccessful = GL_FALSE;

int i, j;

/* Find the corresponding shader */

shader = GLES2_GetShader(type, blendMode);

if (!shader)

{

SDL_SetError("No shader matching the requested characteristics was found");

return NULL;

}

/* Find a matching shader instance that's supported on this hardware */

for (i = 0; i < shader->instance_count && !instance; ++i)

{

{

if (!shader->instances)

continue;

if (!shader->instances[i])

continue;

continue;

instance = shader->instances[i];

}

}

if (!instance)

{

SDL_SetError("The specified shader cannot be loaded on the current platform");

return NULL;

}

/* Check if we've already cached this shader */

while (entry)

{

if (entry->instance == instance)

break;

entry = entry->next;

}

if (entry)

return entry;

/* Create a shader cache entry */

entry = (GLES2_ShaderCacheEntry *)SDL_calloc(1, sizeof(GLES2_ShaderCacheEntry));

if (!entry)

{

SDL_OutOfMemory();

return NULL;

}

entry->type = type;

entry->instance = instance;

/* Compile or load the selected shader instance */

if (instance->format == (GLenum)-1)

{

data->glShaderSource(entry->id, 1, (const char **)&instance->data, NULL);

data->glCompileShader(entry->id);

data->glGetShaderiv(entry->id, GL_COMPILE_STATUS, &compileSuccessful);

}

else

{

compileSuccessful = GL_TRUE;

}

{

char *info = NULL;

int length = 0;

if (length > 0) {

info = SDL_stack_alloc(char, length);

if (info) {

}

}

if (info) {

SDL_SetError("Failed to load the shader: %s", info);

SDL_stack_free(info);

} else {

SDL_SetError("Failed to load the shader");

}

SDL_free(entry);

return NULL;

}

/* Link the shader entry in at the front of the cache */

entry->next = data->shader_cache.head;

data->shader_cache.head->prev = entry;

data->shader_cache.head = entry;

++data->shader_cache.count;

return entry;

}

static void

GLES2_EvictShader(SDL_Renderer *renderer, GLES2_ShaderCacheEntry *entry)

{

/* Unlink the shader from the cache */

if (entry->next)

entry->next->prev = entry->prev;

if (entry->prev)

entry->prev->next = entry->next;

if (data->shader_cache.head == entry)

data->shader_cache.head = entry->next;

--data->shader_cache.count;

/* Deallocate the shader */

SDL_free(entry);

}

static int

GLES2_SelectProgram(SDL_Renderer *renderer, GLES2_ImageSource source, SDL_BlendMode blendMode)

{

GLES2_ShaderCacheEntry *vertex = NULL;

GLES2_ShaderCacheEntry *fragment = NULL;

GLES2_ShaderType vtype, ftype;

GLES2_ProgramCacheEntry *program;

/* Select an appropriate shader pair for the specified modes */

vtype = GLES2_SHADER_VERTEX_DEFAULT;

switch (source)

{

case GLES2_IMAGESOURCE_SOLID:

ftype = GLES2_SHADER_FRAGMENT_SOLID_SRC;

break;

case GLES2_IMAGESOURCE_TEXTURE_ABGR:

ftype = GLES2_SHADER_FRAGMENT_TEXTURE_ABGR_SRC;

break;

case GLES2_IMAGESOURCE_TEXTURE_ARGB:

ftype = GLES2_SHADER_FRAGMENT_TEXTURE_ARGB_SRC;

break;

case GLES2_IMAGESOURCE_TEXTURE_RGB:

ftype = GLES2_SHADER_FRAGMENT_TEXTURE_RGB_SRC;

break;

case GLES2_IMAGESOURCE_TEXTURE_BGR:

ftype = GLES2_SHADER_FRAGMENT_TEXTURE_BGR_SRC;

break;

default:

goto fault;

}

/* Load the requested shaders */

vertex = GLES2_CacheShader(renderer, vtype, blendMode);

if (!vertex)

goto fault;

fragment = GLES2_CacheShader(renderer, ftype, blendMode);

if (!fragment)

goto fault;

/* Check if we need to change programs at all */

if (data->current_program &&

data->current_program->vertex_shader == vertex &&

data->current_program->fragment_shader == fragment)

return 0;