WinRT: merged with latest SDL 2.x/HG code

SDL 2.x recently accepted patches to enable OpenGL ES 2 support via Google's ANGLE library.  The thought is to try to eventually merge SDL/WinRT's OpenGL code with SDL-official's.

src/render/SDL_render.c

@@ -351,8 +351,7 @@ SDL_GetRendererOutputSize(SDL_Renderer * renderer, int *w, int *h)
         return 0;
     } else {
         /* This should never happen */
-        SDL_SetError("Renderer doesn't support querying output size");
-        return -1;
+        return SDL_SetError("Renderer doesn't support querying output size");
     }
 }
 

src/render/opengl/SDL_glfuncs.h

@@ -89,8 +89,8 @@ SDL_PROC_UNUSED(void, glDepthFunc, (GLenum func))
 SDL_PROC_UNUSED(void, glDepthMask, (GLboolean flag))
 SDL_PROC_UNUSED(void, glDepthRange, (GLclampd zNear, GLclampd zFar))
 SDL_PROC(void, glDisable, (GLenum cap))
-SDL_PROC(void, glDisableClientState, (GLenum array))
-SDL_PROC(void, glDrawArrays, (GLenum mode, GLint first, GLsizei count))
+SDL_PROC_UNUSED(void, glDisableClientState, (GLenum array))
+SDL_PROC_UNUSED(void, glDrawArrays, (GLenum mode, GLint first, GLsizei count))
 SDL_PROC_UNUSED(void, glDrawBuffer, (GLenum mode))
 SDL_PROC_UNUSED(void, glDrawElements,
                 (GLenum mode, GLsizei count, GLenum type,
@@ -103,7 +103,7 @@ SDL_PROC_UNUSED(void, glEdgeFlagPointer,
                 (GLsizei stride, const GLvoid * pointer))
 SDL_PROC_UNUSED(void, glEdgeFlagv, (const GLboolean * flag))
 SDL_PROC(void, glEnable, (GLenum cap))
-SDL_PROC(void, glEnableClientState, (GLenum array))
+SDL_PROC_UNUSED(void, glEnableClientState, (GLenum array))
 SDL_PROC(void, glEnd, (void))
 SDL_PROC_UNUSED(void, glEndList, (void))
 SDL_PROC_UNUSED(void, glEvalCoord1d, (GLdouble u))
@@ -448,7 +448,7 @@ SDL_PROC_UNUSED(void, glVertex4iv, (const GLint * v))
 SDL_PROC_UNUSED(void, glVertex4s,
                 (GLshort x, GLshort y, GLshort z, GLshort w))
 SDL_PROC_UNUSED(void, glVertex4sv, (const GLshort * v))
-SDL_PROC(void, glVertexPointer,
+SDL_PROC_UNUSED(void, glVertexPointer,
                 (GLint size, GLenum type, GLsizei stride,
                  const GLvoid * pointer))
 SDL_PROC(void, glViewport, (GLint x, GLint y, GLsizei width, GLsizei height))

src/render/opengl/SDL_render_gl.c

@@ -919,8 +919,16 @@ GL_UpdateViewport(SDL_Renderer * renderer)
         return 0;
     }
 
-    data->glViewport(renderer->viewport.x, renderer->viewport.y,
-                     renderer->viewport.w, renderer->viewport.h);
+    if (renderer->target) {
+        data->glViewport(renderer->viewport.x, renderer->viewport.y,
+                         renderer->viewport.w, renderer->viewport.h);
+    } else {
+        int w, h;
+
+        SDL_GetRendererOutputSize(renderer, &w, &h);
+        data->glViewport(renderer->viewport.x, (h - renderer->viewport.y - renderer->viewport.h),
+                         renderer->viewport.w, renderer->viewport.h);
+    }
 
     data->glMatrixMode(GL_PROJECTION);
     data->glLoadIdentity();
@@ -1048,17 +1056,15 @@ GL_RenderDrawPoints(SDL_Renderer * renderer, const SDL_FPoint * points,
                     int count)
 {
     GL_RenderData *data = (GL_RenderData *) renderer->driverdata;
+    int i;
 
     GL_SetDrawingState(renderer);
 
-    data->glTranslatef(0.5f, 0.5f, 0.0f);
-    data->glVertexPointer(2, GL_FLOAT, 0, points);
-    data->glEnableClientState(GL_VERTEX_ARRAY);
-
-    data->glDrawArrays(GL_POINTS, 0, count);
-
-    data->glDisableClientState(GL_VERTEX_ARRAY);
-    data->glTranslatef(-0.5f, -0.5f, 0.0f);
+    data->glBegin(GL_POINTS);
+    for (i = 0; i < count; ++i) {
+        data->glVertex2f(0.5f + points[i].x, 0.5f + points[i].y);
+    }
+    data->glEnd();
 
     return 0;
 }
@@ -1068,28 +1074,62 @@ GL_RenderDrawLines(SDL_Renderer * renderer, const SDL_FPoint * points,
                    int count)
 {
     GL_RenderData *data = (GL_RenderData *) renderer->driverdata;
+    int i;
 
     GL_SetDrawingState(renderer);
 
-    data->glTranslatef(0.5f, 0.5f, 0.0f);
-    data->glVertexPointer(2, GL_FLOAT, 0, points);
-    data->glEnableClientState(GL_VERTEX_ARRAY);
-
     if (count > 2 &&
         points[0].x == points[count-1].x && points[0].y == points[count-1].y) {
+        data->glBegin(GL_LINE_LOOP);
         /* GL_LINE_LOOP takes care of the final segment */
-        data->glDrawArrays(GL_LINE_LOOP, 0, count-1);
+        --count;
+        for (i = 0; i < count; ++i) {
+            data->glVertex2f(0.5f + points[i].x, 0.5f + points[i].y);
+        }
+        data->glEnd();
     } else {
-        data->glDrawArrays(GL_LINE_STRIP, 0, count);
-    }
-    /* Make sure all the line endpoints are closed.
-     * http://www.opengl.org/documentation/specs/version1.1/glspec1.1/node47.html
-     * Which points need to be drawn varies by driver, so just draw all of them.
-     */
-    data->glDrawArrays(GL_POINTS, 0, count);
-    data->glDisableClientState(GL_VERTEX_ARRAY);
-    data->glTranslatef(-0.5f, -0.5f, 0.0f);
+#if defined(__MACOSX__) || defined(__WIN32__)
+#else
+        int x1, y1, x2, y2;
+#endif
 
+        data->glBegin(GL_LINE_STRIP);
+        for (i = 0; i < count; ++i) {
+            data->glVertex2f(0.5f + points[i].x, 0.5f + points[i].y);
+        }
+        data->glEnd();
+
+        /* The line is half open, so we need one more point to complete it.
+         * http://www.opengl.org/documentation/specs/version1.1/glspec1.1/node47.html
+         * If we have to, we can use vertical line and horizontal line textures
+         * for vertical and horizontal lines, and then create custom textures
+         * for diagonal lines and software render those.  It's terrible, but at
+         * least it would be pixel perfect.
+         */
+        data->glBegin(GL_POINTS);
+#if defined(__MACOSX__) || defined(__WIN32__)
+        /* Mac OS X and Windows seem to always leave the last point open */
+        data->glVertex2f(0.5f + points[count-1].x, 0.5f + points[count-1].y);
+#else
+        /* Linux seems to leave the right-most or bottom-most point open */
+        x1 = points[0].x;
+        y1 = points[0].y;
+        x2 = points[count-1].x;
+        y2 = points[count-1].y;
+
+        if (x1 > x2) {
+            data->glVertex2f(0.5f + x1, 0.5f + y1);
+        } else if (x2 > x1) {
+            data->glVertex2f(0.5f + x2, 0.5f + y2);
+        }
+        if (y1 > y2) {
+            data->glVertex2f(0.5f + x1, 0.5f + y1);
+        } else if (y2 > y1) {
+            data->glVertex2f(0.5f + x2, 0.5f + y2);
+        }
+#endif
+        data->glEnd();
+    }
     return GL_CheckError("", renderer);
 }
 

src/render/opengles2/SDL_gles2funcs.h

@@ -46,3 +46,5 @@ SDL_PROC(void, glBindFramebuffer, (GLenum, GLuint))
 SDL_PROC(void, glFramebufferTexture2D, (GLenum, GLenum, GLenum, GLuint, GLint))
 SDL_PROC(GLenum, glCheckFramebufferStatus, (GLenum))
 SDL_PROC(void, glDeleteFramebuffers, (GLsizei, const GLuint *))
+SDL_PROC(GLint, glGetAttribLocation, (GLuint, const GLchar *))
+