commit 322af82c04792adc19ae299e1beb43bee77743a9
author Sam Lantinga <slouken@libsdl.org> Sun May 19 11:01:36 2019 -0700
committer Sam Lantinga <slouken@libsdl.org> Sun May 19 11:01:36 2019 -0700
tree e52a764322c9746b8c18e7b1db1785f3ce657df3
parent 56fb49c9af5fff56504e2600858fdc27f80411dc

Fixed bug 4025 - SDL_Renderer OpenGL : add support for textures ABGR, RGB, BGR

Sylvain

OpenGLES2 SDL renderer has support for textures ARGB, ABGR, RGB and BGR, whereas OpenGL SDL renderer only had ARGB.

If you think it's worth adding it, here's a patch. I quickly tried and it worked, but there may be missing things or corner case.

src/render/opengl/SDL_render_gl.c

diff --git a/src/render/opengl/SDL_render_gl.c b/src/render/opengl/SDL_render_gl.c
index a32ac6e..6c09e16 100644
--- a/src/render/opengl/SDL_render_gl.c
+++ b/src/render/opengl/SDL_render_gl.c
@@ -405,10 +405,17 @@
 {
     switch (pixel_format) {
     case SDL_PIXELFORMAT_ARGB8888:
+    case SDL_PIXELFORMAT_RGB888:
         *internalFormat = GL_RGBA8;
         *format = GL_BGRA;
         *type = GL_UNSIGNED_INT_8_8_8_8_REV;
         break;
+    case SDL_PIXELFORMAT_ABGR8888:
+    case SDL_PIXELFORMAT_BGR888:
+        *internalFormat = GL_RGBA8;
+        *format = GL_RGBA;
+        *type = GL_UNSIGNED_INT_8_8_8_8_REV;
+        break;
     case SDL_PIXELFORMAT_YV12:
     case SDL_PIXELFORMAT_IYUV:
     case SDL_PIXELFORMAT_NV12:
@@ -1019,7 +1026,13 @@
 {
     SDL_Texture *texture = cmd->data.draw.texture;
     const GL_TextureData *texturedata = (GL_TextureData *) texture->driverdata;
-    GL_Shader shader = SHADER_RGB;
+    GL_Shader shader;
+
+    if (texture->format == SDL_PIXELFORMAT_ABGR8888 || texture->format == SDL_PIXELFORMAT_ARGB8888) {
+        shader = SHADER_RGBA;
+    } else {
+        shader = SHADER_RGB;
+    }
 
     if (data->shaders) {
         if (texturedata->yuv || texturedata->nv12) {
@@ -1733,8 +1746,13 @@
     {
      "opengl",
      (SDL_RENDERER_ACCELERATED | SDL_RENDERER_PRESENTVSYNC | SDL_RENDERER_TARGETTEXTURE),
-     1,
-     {SDL_PIXELFORMAT_ARGB8888},
+     4,
+     {
+         SDL_PIXELFORMAT_ARGB8888,
+         SDL_PIXELFORMAT_ABGR8888,
+         SDL_PIXELFORMAT_RGB888,
+         SDL_PIXELFORMAT_BGR888
+     },
      0,
      0}
 };

src/render/opengl/SDL_shaders_gl.c

diff --git a/src/render/opengl/SDL_shaders_gl.c b/src/render/opengl/SDL_shaders_gl.c
index 7572191..c325973 100644
--- a/src/render/opengl/SDL_shaders_gl.c
+++ b/src/render/opengl/SDL_shaders_gl.c
@@ -240,6 +240,23 @@
 "\n"
 "void main()\n"
 "{\n"
+"    gl_FragColor = texture2D(tex0, v_texCoord);\n"
+"    gl_FragColor.a = 1.0;\n"
+"    gl_FragColor *= v_color;\n"
+"}"
+    },
+
+    /* SHADER_RGBA */
+    {
+        /* vertex shader */
+        TEXTURE_VERTEX_SHADER,
+        /* fragment shader */
+"varying vec4 v_color;\n"
+"varying vec2 v_texCoord;\n"
+"uniform sampler2D tex0;\n"
+"\n"
+"void main()\n"
+"{\n"
 "    gl_FragColor = texture2D(tex0, v_texCoord) * v_color;\n"
 "}"
     },

src/render/opengl/SDL_shaders_gl.h

diff --git a/src/render/opengl/SDL_shaders_gl.h b/src/render/opengl/SDL_shaders_gl.h
index 3638b44..1917e26 100644
--- a/src/render/opengl/SDL_shaders_gl.h
+++ b/src/render/opengl/SDL_shaders_gl.h
@@ -31,6 +31,7 @@
     SHADER_NONE,
     SHADER_SOLID,
     SHADER_RGB,
+    SHADER_RGBA,
     SHADER_YUV_JPEG,
     SHADER_YUV_BT601,
     SHADER_YUV_BT709,