Sean McKean
I am running Ubuntu 12.04 (GL version 1.4 Mesa 8.0.4) , and on drawing a set of lines through the renderer through SDL_RenderDrawLines() (looped or not) or SDL_RenderDrawRect() I notice a pixel missing. For RenderDrawLines() it seems to be the second point in the sequence; for RenderDrawRect() it is the lower-right. This can be fixed by specifying SDL_RenderDrawPoint(s), but wouldn't it be easier to specify each pixel in a GL_POINTS glBegin/End loop in the OpenGL code, just to make sure?
I also ran the same program on Android; the rendering seemed to be correct, which uses glDrawArrays.
Kevin Wells
Overview:
SDL_RenderClear is only clearing part of a texture when it is the render target and a different size than the screen.
Steps to Reproduce:
1) This only occurs with the render driver set to direct3d, so: SDL_SetHint(SDL_HINT_RENDER_DRIVER,"direct3d")
Also, my window was 1280x720.
2) Create a texture for a render target with a resolution of 1024x1024:
texture=SDL_CreateTexture(main_window.renderer,SDL_PIXELFORMAT_RGBA8888,SDL_TEXTUREACCESS_TARGET,1024,1024);
SDL_SetTextureBlendMode(texture,SDL_BLENDMODE_BLEND);
3) Target the texture for rendering: SDL_SetRenderTarget(main_window.renderer,texture);
4) Set the draw color to whatever you want (problem occurs with both 0,0,0,0 and 0,0,0,255 among others) and then clear the render target:
SDL_SetRenderDrawColor(main_window.renderer,0,0,0,0);
SDL_RenderClear(main_window.renderer);
Actual Results:
Only about the top 3/4s of the texture gets cleared on calling SDL_RenderClear. The bottom 1/4 or so does not clear.
Expected Results:
Entire render target should be cleared.
Lloyd Bryant
SDL_CreateTexture() is succeeding (i.e. returning a valid pointer) when the requested horizontal or vertical size of the texture exceeds the maximum allowed by the render. This results in hard-to-understand errors showing up when later attempting to use that texture (such as with SDL_SetRenderTarget()).
Added a reference to SDL_Direct3D9GetAdapterIndex to SDL_test_common.c so SDL will fail to compile if the new symbol isn't included properly.
CR: Jorgen
From Sythical:
Hello, I've created a simple SDL2 application which draws a texture on the screen. The problem I'm having is that if I launch another program which loads the UAC popup or if I lock my PC and then login again, the application stops drawing the texture. I tried adding SDL_Delay(10000) after SDL_RenderPresent(renderer). This made the texture stay on the screen for a little bit but the texture wasn't drawn again after the delay. Here's my code:
#include "SDL.h"
int main(int argc, char *argv[])
{
SDL_Renderer *renderer;
SDL_Window *window;
SDL_Surface *surface;
SDL_Texture *rect_texture;
SDL_Event main_event;
SDL_Rect rect_data;
int enable_vsync = 1;
if(SDL_Init(SDL_INIT_VIDEO) < 0) return 1;
window = SDL_CreateWindow("SDL2 Application", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 600, 600, SDL_WINDOW_RESIZABLE);
renderer = SDL_CreateRenderer(window, -1, enable_vsync ? SDL_RENDERER_ACCELERATED | SDL_RENDERER_PRESENTVSYNC : SDL_RENDERER_ACCELERATED);
SDL_SetRenderDrawColor(renderer, 20, 20, 30, 255);
surface = SDL_LoadBMP("icon.bmp");
rect_texture = SDL_CreateTextureFromSurface(renderer, surface);
rect_data.w = 32; rect_data.h = 32;
rect_data.x = 300; rect_data.y = 300;
while(main_event.type != SDL_QUIT)
{
SDL_PollEvent(&main_event);
SDL_RenderClear(renderer);
SDL_RenderCopy(renderer, rect_texture, NULL, &rect_data);
SDL_RenderPresent(renderer);
}
SDL_DestroyTexture(rect_texture);
SDL_DestroyRenderer(renderer);
SDL_DestroyWindow(window);
SDL_Quit();
return 0;
}
driedfruit
SDL_RenderCopy clips dstrect against the viewport. Then it adjusts the
srcrect by "appropriate" amount of pixels. This amount is actually
wrong, quite a lot, because of the rounding errors introduced in the "*
factor / factor" scale.
real_srcrect.x += (deltax * real_srcrect.w) / dstrect->w;
real_srcrect.w += (deltaw * real_srcrect.w) / dstrect->w;
For example:
I have a 32 x 32 srcrect and a 64 x 64 dstrect. So far the
stretching is done perfectly, by a factor of 2.
Now, consider dstrect being clipped against the viewport, so it becomes
56 x 64. Now, the factor becomes 1.75 ! The adjustment to "srcrect"
can't handle this, cause srcrect is in integers.
And thus we now have incorrect mapping, with dstrect not being in the
right proportion to srcrect.
The problem is most evident when upscaling stuff, like displaying a 8x8
texture with a zoom of 64 or more, and moving it beyond the corners of
the screen. It *looks* really really bad.
Note: RenderCopyEX does no such clipping, and is right to do so. The fix would be to remove any such clipping from RenderCopy too. And then fix the software renderer, because it has the same fault, independently of RenderCopy.
[attached patch]
this leaves Software Renderer buggy, as it does it's own clipping later on
