/*

    SDL - Simple DirectMedia Layer

    Copyright (C) 1997-2009 Sam Lantinga

    This library is free software; you can redistribute it and/or

    modify it under the terms of the GNU Lesser General Public

    License as published by the Free Software Foundation; either

    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,

    but WITHOUT ANY WARRANTY; without even the implied warranty of

    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public

    License along with this library; if not, write to the Free Software

    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga

    slouken@libsdl.org

*/

#include "SDL_config.h"

#if SDL_VIDEO_RENDER_OGL_ES

#include "SDL_video.h"

#include "SDL_opengles.h"

#include "SDL_sysvideo.h"

#include "SDL_pixels_c.h"

#include "SDL_rect_c.h"

#include "SDL_yuv_sw_c.h"

#if defined(__QNXNTO__)

/* Include QNX system header to check QNX version later */

#include <sys/neutrino.h>

#endif /* __QNXNTO__ */

#if defined(SDL_VIDEO_DRIVER_QNXGF)  ||  \

    defined(SDL_VIDEO_DRIVER_PHOTON) ||  \

    defined(SDL_VIDEO_DRIVER_PANDORA)

/* Empty function stub to get OpenGL ES 1.x support without  */

/* OpenGL ES extension GL_OES_draw_texture supported         */

GL_API void GL_APIENTRY

glDrawTexiOES(GLint x, GLint y, GLint z, GLint width, GLint height)

{

    return;

}

#endif /* QNXGF || PHOTON || PANDORA */

/* OpenGL ES 1.1 renderer implementation, based on the OpenGL renderer */

static const float inv255f = 1.0f / 255.0f;

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

static int GLES_ActivateRenderer(SDL_Renderer * renderer);

static int GLES_DisplayModeChanged(SDL_Renderer * renderer);

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

static int GLES_QueryTexturePixels(SDL_Renderer * renderer,

                                   SDL_Texture * texture, void **pixels,

                                   int *pitch);

static int GLES_SetTexturePalette(SDL_Renderer * renderer,

                                  SDL_Texture * texture,

                                  const SDL_Color * colors, int firstcolor,

                                  int ncolors);

static int GLES_GetTexturePalette(SDL_Renderer * renderer,

                                  SDL_Texture * texture, SDL_Color * colors,

                                  int firstcolor, int ncolors);

static int GLES_SetTextureColorMod(SDL_Renderer * renderer,

                                   SDL_Texture * texture);

static int GLES_SetTextureAlphaMod(SDL_Renderer * renderer,

                                   SDL_Texture * texture);

static int GLES_SetTextureBlendMode(SDL_Renderer * renderer,

                                    SDL_Texture * texture);

static int GLES_SetTextureScaleMode(SDL_Renderer * renderer,

                                    SDL_Texture * texture);

static int GLES_UpdateTexture(SDL_Renderer * renderer, SDL_Texture * texture,

                              const SDL_Rect * rect, const void *pixels,

                              int pitch);

static int GLES_LockTexture(SDL_Renderer * renderer, SDL_Texture * texture,

                            const SDL_Rect * rect, int markDirty,

                            void **pixels, int *pitch);

static void GLES_UnlockTexture(SDL_Renderer * renderer,

                               SDL_Texture * texture);

static void GLES_DirtyTexture(SDL_Renderer * renderer, SDL_Texture * texture,

                              int numrects, const SDL_Rect * rects);

static int GLES_RenderDrawPoints(SDL_Renderer * renderer,

                                 const SDL_Point * points, int count);

static int GLES_RenderDrawLines(SDL_Renderer * renderer,

                                const SDL_Point * points, int count);

static int GLES_RenderDrawRects(SDL_Renderer * renderer,

                                const SDL_Rect ** rects, int count);

static int GLES_RenderFillRects(SDL_Renderer * renderer,

                                const SDL_Rect ** rects, int count);

static int GLES_RenderCopy(SDL_Renderer * renderer, SDL_Texture * texture,

                           const SDL_Rect * srcrect,

                           const SDL_Rect * dstrect);

static void GLES_RenderPresent(SDL_Renderer * renderer);

static void GLES_DestroyTexture(SDL_Renderer * renderer,

                                SDL_Texture * texture);

static void GLES_DestroyRenderer(SDL_Renderer * renderer);

SDL_RenderDriver GL_ES_RenderDriver = {

    GLES_CreateRenderer,

    {

     "opengl_es",

     (SDL_RENDERER_SINGLEBUFFER | SDL_RENDERER_PRESENTDISCARD |

      SDL_RENDERER_PRESENTVSYNC | SDL_RENDERER_ACCELERATED),

     (SDL_TEXTUREMODULATE_NONE | SDL_TEXTUREMODULATE_COLOR |

      SDL_TEXTUREMODULATE_ALPHA),

     (SDL_BLENDMODE_NONE | SDL_BLENDMODE_MASK |

      SDL_BLENDMODE_BLEND | SDL_BLENDMODE_ADD | SDL_BLENDMODE_MOD),

     (SDL_TEXTURESCALEMODE_NONE | SDL_TEXTURESCALEMODE_FAST |

      SDL_TEXTURESCALEMODE_SLOW), 5,

     {

      /* OpenGL ES 1.x supported formats list */

      SDL_PIXELFORMAT_ABGR4444,

      SDL_PIXELFORMAT_ABGR1555,

      SDL_PIXELFORMAT_BGR565,

      SDL_PIXELFORMAT_BGR24,

      SDL_PIXELFORMAT_ABGR8888},

     0,

     0}

};

typedef struct

{

    SDL_GLContext context;

    SDL_bool updateSize;

    int blendMode;

#ifndef APIENTRY

#define APIENTRY

#endif

    SDL_bool useDrawTexture;

    SDL_bool GL_OES_draw_texture_supported;

    /* OpenGL ES functions */

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

#include "SDL_glesfuncs.h"

#undef SDL_PROC

} GLES_RenderData;

typedef struct

{

    GLuint texture;

    GLenum type;

    GLfloat texw;

    GLfloat texh;

    GLenum format;

    GLenum formattype;

    void *pixels;

    int pitch;

    SDL_DirtyRectList dirty;

} GLES_TextureData;

static void

GLES_SetError(const char *prefix, GLenum result)

{

    const char *error;

    switch (result) {

    case GL_NO_ERROR:

        error = "GL_NO_ERROR";

        break;

    case GL_INVALID_ENUM:

        error = "GL_INVALID_ENUM";

        break;

    case GL_INVALID_VALUE:

        error = "GL_INVALID_VALUE";

        break;

    case GL_INVALID_OPERATION:

        error = "GL_INVALID_OPERATION";

        break;

    case GL_STACK_OVERFLOW:

        error = "GL_STACK_OVERFLOW";

        break;

    case GL_STACK_UNDERFLOW:

        error = "GL_STACK_UNDERFLOW";

        break;

    case GL_OUT_OF_MEMORY:

        error = "GL_OUT_OF_MEMORY";

        break;

    default:

        error = "UNKNOWN";

        break;

    }

    SDL_SetError("%s: %s", prefix, error);

}

static int

GLES_LoadFunctions(GLES_RenderData * data)

{

#define SDL_PROC(ret,func,params) \

    data->func = func;

#include "SDL_glesfuncs.h"

#undef SDL_PROC

    return 0;

}

SDL_Renderer *

GLES_CreateRenderer(SDL_Window * window, Uint32 flags)

{

    SDL_Renderer *renderer;

    GLES_RenderData *data;

    GLint value;

    int doublebuffer;

    if (!(window->flags & SDL_WINDOW_OPENGL)) {

        if (SDL_RecreateWindow(window, window->flags | SDL_WINDOW_OPENGL) < 0) {

            return NULL;

        }

    }

    renderer = (SDL_Renderer *) SDL_calloc(1, sizeof(*renderer));

    if (!renderer) {

        SDL_OutOfMemory();

        return NULL;

    }

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

    if (!data) {

        GLES_DestroyRenderer(renderer);

        SDL_OutOfMemory();

        return NULL;

    }

    renderer->ActivateRenderer = GLES_ActivateRenderer;

    renderer->DisplayModeChanged = GLES_DisplayModeChanged;

    renderer->CreateTexture = GLES_CreateTexture;

    renderer->QueryTexturePixels = GLES_QueryTexturePixels;

    renderer->SetTexturePalette = GLES_SetTexturePalette;

    renderer->GetTexturePalette = GLES_GetTexturePalette;

    renderer->SetTextureColorMod = GLES_SetTextureColorMod;

    renderer->SetTextureAlphaMod = GLES_SetTextureAlphaMod;

    renderer->SetTextureBlendMode = GLES_SetTextureBlendMode;

    renderer->SetTextureScaleMode = GLES_SetTextureScaleMode;

    renderer->UpdateTexture = GLES_UpdateTexture;

    renderer->LockTexture = GLES_LockTexture;

    renderer->UnlockTexture = GLES_UnlockTexture;

    renderer->DirtyTexture = GLES_DirtyTexture;

    renderer->RenderDrawPoints = GLES_RenderDrawPoints;

    renderer->RenderDrawLines = GLES_RenderDrawLines;

    renderer->RenderDrawRects = GLES_RenderDrawRects;

    renderer->RenderFillRects = GLES_RenderFillRects;

    renderer->RenderCopy = GLES_RenderCopy;

    renderer->RenderPresent = GLES_RenderPresent;

    renderer->DestroyTexture = GLES_DestroyTexture;

    renderer->DestroyRenderer = GLES_DestroyRenderer;

    renderer->info = GL_ES_RenderDriver.info;

    renderer->window = window->id;

    renderer->driverdata = data;

    renderer->info.flags =

        (SDL_RENDERER_PRESENTDISCARD | SDL_RENDERER_ACCELERATED);

#if defined(__QNXNTO__)

#if _NTO_VERSION<=641

    /* QNX's OpenGL ES implementation is broken regarding             */

    /* packed textures support, affected versions 6.3.2, 6.4.0, 6.4.1 */

    renderer->info.num_texture_formats = 2;

    renderer->info.texture_formats[0] = SDL_PIXELFORMAT_ABGR8888;

    renderer->info.texture_formats[1] = SDL_PIXELFORMAT_BGR24;

#endif /* _NTO_VERSION */

#endif /* __QNXNTO__ */

    if (GLES_LoadFunctions(data) < 0) {

        GLES_DestroyRenderer(renderer);

        return NULL;

    }

    data->context = SDL_GL_CreateContext(window->id);

    if (!data->context) {

        GLES_DestroyRenderer(renderer);

        return NULL;

    }

    if (SDL_GL_MakeCurrent(window->id, data->context) < 0) {

        GLES_DestroyRenderer(renderer);

        return NULL;

    }

    if (flags & SDL_RENDERER_PRESENTVSYNC) {

        SDL_GL_SetSwapInterval(1);

    } else {

        SDL_GL_SetSwapInterval(0);

    }

    if (SDL_GL_GetSwapInterval() > 0) {

        renderer->info.flags |= SDL_RENDERER_PRESENTVSYNC;

    }

    if (SDL_GL_GetAttribute(SDL_GL_DOUBLEBUFFER, &doublebuffer) == 0) {

        if (!doublebuffer) {

            renderer->info.flags |= SDL_RENDERER_SINGLEBUFFER;

        }

    }

#if SDL_VIDEO_DRIVER_PANDORA

    data->GL_OES_draw_texture_supported = SDL_FALSE;

    data->useDrawTexture = SDL_FALSE;

#else

    if (SDL_GL_ExtensionSupported("GL_OES_draw_texture")) {

        data->GL_OES_draw_texture_supported = SDL_TRUE;

        data->useDrawTexture = SDL_TRUE;

    } else {

        data->GL_OES_draw_texture_supported = SDL_FALSE;

        data->useDrawTexture = SDL_FALSE;

    }

#endif

    data->glGetIntegerv(GL_MAX_TEXTURE_SIZE, &value);

    renderer->info.max_texture_width = value;

    data->glGetIntegerv(GL_MAX_TEXTURE_SIZE, &value);

    renderer->info.max_texture_height = value;

    /* Set up parameters for rendering */

    data->blendMode = -1;

    data->glDisable(GL_DEPTH_TEST);

    data->glDisable(GL_CULL_FACE);

    data->updateSize = SDL_TRUE;

    return renderer;

}

static int

GLES_ActivateRenderer(SDL_Renderer * renderer)

{

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

    SDL_Window *window = renderer->window;

    if (SDL_GL_MakeCurrent(window->id, data->context) < 0) {

        return -1;

    }

    if (data->updateSize) {

        data->glMatrixMode(GL_PROJECTION);

        data->glLoadIdentity();

        data->glMatrixMode(GL_MODELVIEW);

        data->glLoadIdentity();

        data->glViewport(0, 0, window->w, window->h);

        data->glOrthof(0.0, (GLfloat) window->w, (GLfloat) window->h, 0.0,

                       0.0, 1.0);

        data->updateSize = SDL_FALSE;

    }

    return 0;

}

static int

GLES_DisplayModeChanged(SDL_Renderer * renderer)

{

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

    data->updateSize = SDL_TRUE;

    return 0;

}

static __inline__ int

power_of_2(int input)

{

    int value = 1;

    while (value < input) {

        value <<= 1;

    }

    return value;

}

static int

GLES_CreateTexture(SDL_Renderer * renderer, SDL_Texture * texture)

{

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

    GLES_TextureData *data;

    GLint internalFormat;

    GLenum format, type;

    int texture_w, texture_h;

    GLenum result;

    switch (texture->format) {

    case SDL_PIXELFORMAT_BGR24:

        internalFormat = GL_RGB;

        format = GL_RGB;

        type = GL_UNSIGNED_BYTE;

        break;

    case SDL_PIXELFORMAT_ABGR8888:

        internalFormat = GL_RGBA;

        format = GL_RGBA;

        type = GL_UNSIGNED_BYTE;

        break;

    case SDL_PIXELFORMAT_BGR565:

        internalFormat = GL_RGB;

        format = GL_RGB;

        type = GL_UNSIGNED_SHORT_5_6_5;

        break;

    case SDL_PIXELFORMAT_ABGR1555:

        internalFormat = GL_RGBA;

        format = GL_RGBA;

        type = GL_UNSIGNED_SHORT_5_5_5_1;

        break;

    case SDL_PIXELFORMAT_ABGR4444:

        internalFormat = GL_RGBA;

        format = GL_RGBA;

        type = GL_UNSIGNED_SHORT_4_4_4_4;

        break;

    default:

        SDL_SetError("Unsupported by OpenGL ES texture format");

        return -1;

    }

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

    if (!data) {

        SDL_OutOfMemory();

        return -1;

    }

    if (texture->access == SDL_TEXTUREACCESS_STREAMING) {

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

        data->pixels = SDL_malloc(texture->h * data->pitch);

        if (!data->pixels) {

            SDL_OutOfMemory();

            SDL_free(data);

            return -1;

        }

    }

    texture->driverdata = data;

    renderdata->glGetError();

    renderdata->glEnable(GL_TEXTURE_2D);

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

    data->type = GL_TEXTURE_2D;

    /* no NPOV textures allowed in OpenGL ES (yet) */

    texture_w = power_of_2(texture->w);

    texture_h = power_of_2(texture->h);

    data->texw = (GLfloat) texture->w / texture_w;

    data->texh = (GLfloat) texture->h / texture_h;

    data->format = format;

    data->formattype = type;

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

    renderdata->glTexParameteri(data->type, GL_TEXTURE_MIN_FILTER,

                                GL_NEAREST);

    renderdata->glTexParameteri(data->type, GL_TEXTURE_MAG_FILTER,

                                GL_NEAREST);

    renderdata->glTexParameteri(data->type, GL_TEXTURE_WRAP_S,

                                GL_CLAMP_TO_EDGE);

    renderdata->glTexParameteri(data->type, GL_TEXTURE_WRAP_T,

                                GL_CLAMP_TO_EDGE);

    renderdata->glTexImage2D(data->type, 0, internalFormat, texture_w,

                             texture_h, 0, format, type, NULL);

    renderdata->glDisable(GL_TEXTURE_2D);

    result = renderdata->glGetError();

    if (result != GL_NO_ERROR) {

        GLES_SetError("glTexImage2D()", result);

        return -1;

    }

    return 0;

}

static int

GLES_QueryTexturePixels(SDL_Renderer * renderer, SDL_Texture * texture,

                        void **pixels, int *pitch)

{

    GLES_TextureData *data = (GLES_TextureData *) texture->driverdata;

    *pixels = data->pixels;

    *pitch = data->pitch;

    return 0;

}

static int

GLES_SetTexturePalette(SDL_Renderer * renderer, SDL_Texture * texture,

                       const SDL_Color * colors, int firstcolor, int ncolors)

{

    SDL_SetError("OpenGL ES does not support paletted textures");

    return -1;

}

static int

GLES_GetTexturePalette(SDL_Renderer * renderer, SDL_Texture * texture,

                       SDL_Color * colors, int firstcolor, int ncolors)

{

    SDL_SetError("OpenGL ES does not support paletted textures");

    return -1;

}

static void

SetupTextureUpdate(GLES_RenderData * renderdata, SDL_Texture * texture,

                   int pitch)

{

    GLES_TextureData *data = (GLES_TextureData *) texture->driverdata;

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

    renderdata->glPixelStorei(GL_UNPACK_ALIGNMENT, 1);

}

static int

GLES_SetTextureColorMod(SDL_Renderer * renderer, SDL_Texture * texture)

{

    return 0;

}

static int

GLES_SetTextureAlphaMod(SDL_Renderer * renderer, SDL_Texture * texture)

{

    return 0;

}

static int

GLES_SetTextureBlendMode(SDL_Renderer * renderer, SDL_Texture * texture)

{

    switch (texture->blendMode) {

    case SDL_BLENDMODE_NONE:

    case SDL_BLENDMODE_MASK:

    case SDL_BLENDMODE_BLEND:

    case SDL_BLENDMODE_ADD:

    case SDL_BLENDMODE_MOD:

        return 0;

    default:

        SDL_Unsupported();

        texture->blendMode = SDL_BLENDMODE_NONE;

        return -1;

    }

}

static int

GLES_SetTextureScaleMode(SDL_Renderer * renderer, SDL_Texture * texture)

{

    switch (texture->scaleMode) {

    case SDL_TEXTURESCALEMODE_NONE:

    case SDL_TEXTURESCALEMODE_FAST:

    case SDL_TEXTURESCALEMODE_SLOW:

        return 0;

    case SDL_TEXTURESCALEMODE_BEST:

        SDL_Unsupported();

        texture->scaleMode = SDL_TEXTURESCALEMODE_SLOW;

        return -1;

    default:

        SDL_Unsupported();

        texture->scaleMode = SDL_TEXTURESCALEMODE_NONE;

        return -1;

    }

}

static int

GLES_UpdateTexture(SDL_Renderer * renderer, SDL_Texture * texture,

                   const SDL_Rect * rect, const void *pixels, int pitch)

{

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

    GLES_TextureData *data = (GLES_TextureData *) texture->driverdata;

    GLenum result;

    renderdata->glGetError();

    renderdata->glEnable(data->type);

    SetupTextureUpdate(renderdata, texture, pitch);

    renderdata->glTexSubImage2D(data->type, 0, rect->x, rect->y, rect->w,

                                rect->h, data->format, data->formattype,

                                pixels);

    renderdata->glDisable(data->type);

    result = renderdata->glGetError();

    if (result != GL_NO_ERROR) {

        GLES_SetError("glTexSubImage2D()", result);

        return -1;

    }

    return 0;

}

static int

GLES_LockTexture(SDL_Renderer * renderer, SDL_Texture * texture,

                 const SDL_Rect * rect, int markDirty, void **pixels,

                 int *pitch)

{

    GLES_TextureData *data = (GLES_TextureData *) texture->driverdata;

    if (markDirty) {

        SDL_AddDirtyRect(&data->dirty, rect);

    }

    *pixels =

        (void *) ((Uint8 *) data->pixels + rect->y * data->pitch +

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

    *pitch = data->pitch;

    return 0;

}

static void

GLES_UnlockTexture(SDL_Renderer * renderer, SDL_Texture * texture)

{

}

static void

GLES_DirtyTexture(SDL_Renderer * renderer, SDL_Texture * texture,

                  int numrects, const SDL_Rect * rects)

{

    GLES_TextureData *data = (GLES_TextureData *) texture->driverdata;

    int i;

    for (i = 0; i < numrects; ++i) {

        SDL_AddDirtyRect(&data->dirty, &rects[i]);

    }

}

static void

GLES_SetBlendMode(GLES_RenderData * data, int blendMode, int isprimitive)

{

    if (blendMode != data->blendMode) {

        switch (blendMode) {

        case SDL_BLENDMODE_NONE:

            data->glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);

            data->glDisable(GL_BLEND);

            break;

        case SDL_BLENDMODE_MASK:

            if (isprimitive) {

                data->glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);

                data->glDisable(GL_BLEND);

                /* The same as SDL_BLENDMODE_NONE */

                blendMode = SDL_BLENDMODE_NONE;

                break;

            }

            /* fall through */

        case SDL_BLENDMODE_BLEND:

            data->glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);

            data->glEnable(GL_BLEND);

            data->glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

            break;

        case SDL_BLENDMODE_ADD:

            data->glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);

            data->glEnable(GL_BLEND);

            data->glBlendFunc(GL_SRC_ALPHA, GL_ONE);

            break;

        case SDL_BLENDMODE_MOD:

            data->glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);

            data->glEnable(GL_BLEND);

            data->glBlendFunc(GL_ZERO, GL_SRC_COLOR);

            break;

        }

        data->blendMode = blendMode;

    }

}

static int

GLES_RenderDrawPoints(SDL_Renderer * renderer, const SDL_Point * points,

                      int count)

{

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

    int i;

    GLshort *vertices;

    GLES_SetBlendMode(data, renderer->blendMode, 1);

    data->glColor4f((GLfloat) renderer->r * inv255f,

                    (GLfloat) renderer->g * inv255f,

                    (GLfloat) renderer->b * inv255f,

                    (GLfloat) renderer->a * inv255f);

    vertices = SDL_stack_alloc(GLshort, count*2);

    for (i = 0; i < count; ++i) {

        vertices[2*i+0] = (GLshort)points[i].x;

        vertices[2*i+1] = (GLshort)points[i].y;

    }

    data->glVertexPointer(2, GL_SHORT, 0, vertices);

    data->glEnableClientState(GL_VERTEX_ARRAY);

    data->glDrawArrays(GL_POINTS, 0, count);

    data->glDisableClientState(GL_VERTEX_ARRAY);

    SDL_stack_free(vertices);

    return 0;

}

static int

GLES_RenderDrawLines(SDL_Renderer * renderer, const SDL_Point * points,

                     int count)

{

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

    int i;

    GLshort *vertices;

    GLES_SetBlendMode(data, renderer->blendMode, 1);

    data->glColor4f((GLfloat) renderer->r * inv255f,

                    (GLfloat) renderer->g * inv255f,

                    (GLfloat) renderer->b * inv255f,

                    (GLfloat) renderer->a * inv255f);

    vertices = SDL_stack_alloc(GLshort, count*2);

    for (i = 0; i < count; ++i) {

        vertices[2*i+0] = (GLshort)points[i].x;

        vertices[2*i+1] = (GLshort)points[i].y;

    }

    data->glVertexPointer(2, GL_SHORT, 0, vertices);

    data->glEnableClientState(GL_VERTEX_ARRAY);

    if (count > 2 && 

        points[0].x == points[count-1].x && points[0].y == points[count-1].y) {

        /* GL_LINE_LOOP takes care of the final segment */

        --count;

        data->glDrawArrays(GL_LINE_LOOP, 0, count);

    } else {

        data->glDrawArrays(GL_LINE_STRIP, 0, count);

    }

    data->glDisableClientState(GL_VERTEX_ARRAY);

    SDL_stack_free(vertices);

    return 0;

}

static int

GLES_RenderDrawRects(SDL_Renderer * renderer, const SDL_Rect ** rects,

                     int count)

{

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

    int i;

    GLES_SetBlendMode(data, renderer->blendMode, 1);

    data->glColor4f((GLfloat) renderer->r * inv255f,

                    (GLfloat) renderer->g * inv255f,

                    (GLfloat) renderer->b * inv255f,

                    (GLfloat) renderer->a * inv255f);

    data->glEnableClientState(GL_VERTEX_ARRAY);

    for (i = 0; i < count; ++i) {

        const SDL_Rect *rect = rects[i];

        GLshort minx = rect->x;

        GLshort maxx = rect->x + rect->w;

        GLshort miny = rect->y;

        GLshort maxy = rect->y + rect->h;

        GLshort vertices[8];

        vertices[0] = minx;

        vertices[1] = miny;

        vertices[2] = maxx;

        vertices[3] = miny;

        vertices[4] = minx;

        vertices[5] = maxy;

        vertices[6] = maxx;

        vertices[7] = maxy;

        data->glVertexPointer(2, GL_SHORT, 0, vertices);

        data->glDrawArrays(GL_LINE_LOOP, 0, 4);

    }

    data->glDisableClientState(GL_VERTEX_ARRAY);

    return 0;

}

static int

GLES_RenderFillRects(SDL_Renderer * renderer, const SDL_Rect ** rects,

                     int count)

{

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

    int i;

    GLES_SetBlendMode(data, renderer->blendMode, 1);

    data->glColor4f((GLfloat) renderer->r * inv255f,

                    (GLfloat) renderer->g * inv255f,

                    (GLfloat) renderer->b * inv255f,

                    (GLfloat) renderer->a * inv255f);

    data->glEnableClientState(GL_VERTEX_ARRAY);

    for (i = 0; i < count; ++i) {

        const SDL_Rect *rect = rects[i];

        GLshort minx = rect->x;

        GLshort maxx = rect->x + rect->w;

        GLshort miny = rect->y;

        GLshort maxy = rect->y + rect->h;

        GLshort vertices[8];

        vertices[0] = minx;

        vertices[1] = miny;

        vertices[2] = maxx;

        vertices[3] = miny;

        vertices[4] = minx;

        vertices[5] = maxy;

        vertices[6] = maxx;

        vertices[7] = maxy;

        data->glVertexPointer(2, GL_SHORT, 0, vertices);

        data->glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);

    }

    data->glDisableClientState(GL_VERTEX_ARRAY);

    return 0;

}

static int

GLES_RenderCopy(SDL_Renderer * renderer, SDL_Texture * texture,

                const SDL_Rect * srcrect, const SDL_Rect * dstrect)

{

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

    GLES_TextureData *texturedata = (GLES_TextureData *) texture->driverdata;

    int minx, miny, maxx, maxy;

    GLfloat minu, maxu, minv, maxv;

    int i;

    void *temp_buffer;          /* used for reformatting dirty rect pixels */

    void *temp_ptr;

    data->glEnable(GL_TEXTURE_2D);

    if (texturedata->dirty.list) {

        SDL_DirtyRect *dirty;

        void *pixels;

        int bpp = SDL_BYTESPERPIXEL(texture->format);

        int pitch = texturedata->pitch;

        SetupTextureUpdate(data, texture, pitch);

        data->glBindTexture(texturedata->type, texturedata->texture);

        for (dirty = texturedata->dirty.list; dirty; dirty = dirty->next) {

            SDL_Rect *rect = &dirty->rect;

            pixels =

                (void *) ((Uint8 *) texturedata->pixels + rect->y * pitch +

                          rect->x * bpp);

            /*      There is no GL_UNPACK_ROW_LENGTH in OpenGLES 

               we must do this reformatting ourselves(!)

               maybe it'd be a good idea to keep a temp buffer around

               for this purpose rather than allocating it each time

             */

            temp_buffer = SDL_malloc(rect->w * rect->h * bpp);

            temp_ptr = temp_buffer;

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

                SDL_memcpy(temp_ptr, pixels, rect->w * bpp);

                temp_ptr += rect->w * bpp;

                pixels += pitch;

            }

            data->glTexSubImage2D(texturedata->type, 0, rect->x, rect->y,

                                  rect->w, rect->h, texturedata->format,

                                  texturedata->formattype, temp_buffer);

            SDL_free(temp_buffer);

        }

        SDL_ClearDirtyRects(&texturedata->dirty);

    }

    data->glBindTexture(texturedata->type, texturedata->texture);

    if (texture->modMode) {

        data->glColor4f((GLfloat) texture->r * inv255f,

                        (GLfloat) texture->g * inv255f,

                        (GLfloat) texture->b * inv255f,

                        (GLfloat) texture->a * inv255f);

    } else {

        data->glColor4f(1.0f, 1.0f, 1.0f, 1.0f);

    }

    GLES_SetBlendMode(data, texture->blendMode, 0);

    switch (texture->scaleMode) {

    case SDL_TEXTURESCALEMODE_NONE:

    case SDL_TEXTURESCALEMODE_FAST:

        data->glTexParameteri(texturedata->type, GL_TEXTURE_MIN_FILTER,

                              GL_NEAREST);

        data->glTexParameteri(texturedata->type, GL_TEXTURE_MAG_FILTER,

                              GL_NEAREST);

        break;

    case SDL_TEXTURESCALEMODE_SLOW:

    case SDL_TEXTURESCALEMODE_BEST:

        data->glTexParameteri(texturedata->type, GL_TEXTURE_MIN_FILTER,

                              GL_LINEAR);

        data->glTexParameteri(texturedata->type, GL_TEXTURE_MAG_FILTER,

                              GL_LINEAR);

        break;

    }

    if (data->GL_OES_draw_texture_supported && data->useDrawTexture) {

        /* this code is a little funny because the viewport is upside down vs SDL's coordinate system */

        SDL_Window *window = renderer->window;

        GLint cropRect[4];

        cropRect[0] = srcrect->x;

        cropRect[1] = srcrect->y + srcrect->h;

        cropRect[2] = srcrect->w;

        cropRect[3] = -srcrect->h;

        data->glTexParameteriv(GL_TEXTURE_2D, GL_TEXTURE_CROP_RECT_OES,

                               cropRect);

        data->glDrawTexiOES(dstrect->x, window->h - dstrect->y - dstrect->h,

                            0, dstrect->w, dstrect->h);

    } else {

        minx = dstrect->x;

        miny = dstrect->y;

        maxx = dstrect->x + dstrect->w;

        maxy = dstrect->y + dstrect->h;

        minu = (GLfloat) srcrect->x / texture->w;

        minu *= texturedata->texw;

        maxu = (GLfloat) (srcrect->x + srcrect->w) / texture->w;

        maxu *= texturedata->texw;

        minv = (GLfloat) srcrect->y / texture->h;

        minv *= texturedata->texh;

        maxv = (GLfloat) (srcrect->y + srcrect->h) / texture->h;

        maxv *= texturedata->texh;

        GLshort vertices[8];

        GLfloat texCoords[8];

        vertices[0] = minx;

        vertices[1] = miny;

        vertices[2] = maxx;

        vertices[3] = miny;

        vertices[4] = minx;

        vertices[5] = maxy;

        vertices[6] = maxx;

        vertices[7] = maxy;

        texCoords[0] = minu;

        texCoords[1] = minv;

        texCoords[2] = maxu;

        texCoords[3] = minv;

        texCoords[4] = minu;

        texCoords[5] = maxv;

        texCoords[6] = maxu;

        texCoords[7] = maxv;

        data->glVertexPointer(2, GL_SHORT, 0, vertices);

        data->glEnableClientState(GL_VERTEX_ARRAY);

        data->glTexCoordPointer(2, GL_FLOAT, 0, texCoords);

        data->glEnableClientState(GL_TEXTURE_COORD_ARRAY);

        data->glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);

        data->glDisableClientState(GL_TEXTURE_COORD_ARRAY);

        data->glDisableClientState(GL_VERTEX_ARRAY);

    }

    data->glDisable(GL_TEXTURE_2D);

    return 0;

}

static void

GLES_RenderPresent(SDL_Renderer * renderer)

{

    SDL_GL_SwapWindow(renderer->window);

}

static void

GLES_DestroyTexture(SDL_Renderer * renderer, SDL_Texture * texture)

{

    GLES_TextureData *data = (GLES_TextureData *) texture->driverdata;

    if (!data) {

        return;

    }

    if (data->texture) {

        glDeleteTextures(1, &data->texture);

    }

    if (data->pixels) {

        SDL_free(data->pixels);

    }

    SDL_FreeDirtyRects(&data->dirty);

    SDL_free(data);

    texture->driverdata = NULL;

}

static void

GLES_DestroyRenderer(SDL_Renderer * renderer)

{

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

    if (data) {

        if (data->context) {

            SDL_GL_DeleteContext(data->context);

        }

        SDL_free(data);

    }

    SDL_free(renderer);

}

#endif /* SDL_VIDEO_RENDER_OGL_ES */

/* vi: set ts=4 sw=4 expandtab: */