Fixes OpenGL* Clip Rect functions (by Emmanuel Gil Peyrot)

src/render/opengl/SDL_render_gl.c

@@ -794,7 +794,7 @@ GL_UpdateClipRect(SDL_Renderer * renderer)
 
     if (!SDL_RectEmpty(rect)) {
         data->glEnable(GL_SCISSOR_TEST);
-        data->glScissor(rect->x, rect->y, rect->x + rect->w, rect->y + rect->h);
+        data->glScissor(rect->x, rect->h - rect->y, rect->x, rect->y);
     } else {
         data->glDisable(GL_SCISSOR_TEST);
     }

src/render/opengles/SDL_glesfuncs.h

@@ -20,6 +20,7 @@ SDL_PROC(void, glMatrixMode, (GLenum))
 SDL_PROC(void, glOrthof, (GLfloat, GLfloat, GLfloat, GLfloat, GLfloat, GLfloat))
 SDL_PROC(void, glPixelStorei, (GLenum, GLint))
 SDL_PROC(void, glReadPixels, (GLint, GLint, GLsizei, GLsizei, GLenum, GLenum, GLvoid*))
+SDL_PROC(void, glScissor, (GLint, GLint, GLsizei, GLsizei))
 SDL_PROC(void, glTexCoordPointer, (GLint, GLenum, GLsizei, const GLvoid *))
 SDL_PROC(void, glTexEnvf, (GLenum, GLenum, GLfloat))
 SDL_PROC(void, glTexImage2D, (GLenum, GLint, GLint, GLsizei, GLsizei, GLint, GLenum, GLenum, const GLvoid *))

src/render/opengles/SDL_render_gles.c

@@ -635,13 +635,19 @@ GLES_UpdateViewport(SDL_Renderer * renderer)
 static int
 GLES_UpdateClipRect(SDL_Renderer * renderer)
 {
+    GLES_RenderData *data = (GLES_RenderData *) renderer->driverdata;
     const SDL_Rect *rect = &renderer->clip_rect;
 
+    if (SDL_CurrentContext != data->context) {
+        /* We'll update the clip rect after we rebind the context */
+        return 0;
+    }
+
     if (!SDL_RectEmpty(rect)) {
-        glEnable(GL_SCISSOR_TEST);
-        glScissor(rect->x, rect->y, rect->x + rect->w, rect->y + rect->h);
+        data->glEnable(GL_SCISSOR_TEST);
+        data->glScissor(rect->x, rect->h - rect->y, rect->w, rect->h);
     } else {
-        glDisable(GL_SCISSOR_TEST);
+        data->glDisable(GL_SCISSOR_TEST);
     }
     return 0;
 }

src/render/opengles2/SDL_gles2funcs.h

@@ -30,6 +30,7 @@ SDL_PROC(GLint, glGetUniformLocation, (GLuint, const char *))
 SDL_PROC(void, glLinkProgram, (GLuint))
 SDL_PROC(void, glPixelStorei, (GLenum, GLint))
 SDL_PROC(void, glReadPixels, (GLint, GLint, GLsizei, GLsizei, GLenum, GLenum, GLvoid*))
+SDL_PROC(void, glScissor, (GLint, GLint, GLsizei, GLsizei))
 SDL_PROC(void, glShaderBinary, (GLsizei, const GLuint *, GLenum, const void *, GLsizei))
 SDL_PROC(void, glShaderSource, (GLuint, GLsizei, const char **, const GLint *))
 SDL_PROC(void, glTexImage2D, (GLenum, GLint, GLint, GLsizei, GLsizei, GLint, GLenum, GLenum, const void *))

src/render/opengles2/SDL_render_gles2.c

@@ -278,13 +278,19 @@ GLES2_UpdateViewport(SDL_Renderer * renderer)
 static int
 GLES2_UpdateClipRect(SDL_Renderer * renderer)
 {
+    GLES2_DriverContext *rdata = (GLES2_DriverContext *)renderer->driverdata;
     const SDL_Rect *rect = &renderer->clip_rect;
 
+    if (SDL_CurrentContext != rdata->context) {
+        /* We'll update the clip rect after we rebind the context */
+        return 0;
+    }
+
     if (!SDL_RectEmpty(rect)) {
-        glEnable(GL_SCISSOR_TEST);
-        glScissor(rect->x, rect->y, rect->x + rect->w, rect->y + rect->h);
+        rdata->glEnable(GL_SCISSOR_TEST);
+        rdata->glScissor(rect->x, rect->h - rect->y, rect->w, rect->h);
     } else {
-        glDisable(GL_SCISSOR_TEST);
+        rdata->glDisable(GL_SCISSOR_TEST);
     }
     return 0;
 }