diff --git a/src/Fl_Gl_Choice.cxx b/src/Fl_Gl_Choice.cxx index 3fbce41f7..c0e337674 100644 --- a/src/Fl_Gl_Choice.cxx +++ b/src/Fl_Gl_Choice.cxx @@ -137,6 +137,16 @@ void Fl_Cocoa_Gl_Window_Driver::delete_gl_context(GLContext context) { #include "drivers/WinAPI/Fl_WinAPI_Window_Driver.H" extern void fl_save_dc(HWND, HDC); +// STR #3191: select pixel format with composition support +// ... and no more than 32 color bits (8 bits/color) +// Ref: PixelFormatDescriptor Object +// https://msdn.microsoft.com/en-us/library/cc231189.aspx +#if !defined(PFD_SUPPORT_COMPOSITION) +# define PFD_SUPPORT_COMPOSITION (0x8000) +#endif + +#define DEBUG_PFD (0) // 1 = PFD selection debug output, 0 = no debug output + Fl_Gl_Choice *Fl_WinAPI_Gl_Window_Driver::find(int m, const int *alistp) { Fl_Gl_Choice *g = Fl_Gl_Window_Driver::find_begin(m, alistp); @@ -159,21 +169,47 @@ Fl_Gl_Choice *Fl_WinAPI_Gl_Window_Driver::find(int m, const int *alistp) if ((!(m & FL_STEREO)) != (!(pfd.dwFlags & PFD_STEREO))) continue; if ((m & FL_DEPTH) && !pfd.cDepthBits) continue; if ((m & FL_STENCIL) && !pfd.cStencilBits) continue; + +#if DEBUG_PFD + printf("pfd #%d supports composition: %s\n", i, (pfd.dwFlags & PFD_SUPPORT_COMPOSITION) ? "yes" : "no"); + printf(" ... & PFD_GENERIC_FORMAT: %s\n", (pfd.dwFlags & PFD_GENERIC_FORMAT) ? "generic" : "accelerated"); + printf(" ... Overlay Planes : %d\n", pfd.bReserved & 15); + printf(" ... Color & Depth : %d, %d\n", pfd.cColorBits, pfd.cDepthBits); + if (pixelformat) + printf(" current pixelformat : %d\n", pixelformat); + fflush(stdout); +#endif // DEBUG_PFD + // see if better than the one we have already: if (pixelformat) { - // offering non-generic rendering is better (read: hardware accelleration) + // offering non-generic rendering is better (read: hardware acceleration) if (!(chosen_pfd.dwFlags & PFD_GENERIC_FORMAT) && (pfd.dwFlags & PFD_GENERIC_FORMAT)) continue; // offering overlay is better: else if (!(chosen_pfd.bReserved & 15) && (pfd.bReserved & 15)) {} - // otherwise more bit planes is better: - else if (chosen_pfd.cColorBits > pfd.cColorBits) continue; + // otherwise prefer a format that supports composition (STR #3119) + else if ((chosen_pfd.dwFlags & PFD_SUPPORT_COMPOSITION) && + !(pfd.dwFlags & PFD_SUPPORT_COMPOSITION)) continue; + // otherwise more bit planes is better, but no more than 32 (8 bits per channel): + else if (pfd.cColorBits > 32 || chosen_pfd.cColorBits > pfd.cColorBits) continue; else if (chosen_pfd.cDepthBits > pfd.cDepthBits) continue; } pixelformat = i; chosen_pfd = pfd; } - //printf("Chosen pixel format is %d\n", pixelformat); + +#if DEBUG_PFD + static int bb = 0; + if (!bb) { + bb = 1; + printf("PFD_SUPPORT_COMPOSITION = 0x%x\n", PFD_SUPPORT_COMPOSITION); + } + printf("Chosen pixel format is %d\n", pixelformat); + printf("Color bits = %d, Depth bits = %d\n", chosen_pfd.cColorBits, chosen_pfd.cDepthBits); + printf("Pixel format supports composition: %s\n", (chosen_pfd.dwFlags & PFD_SUPPORT_COMPOSITION) ? "yes" : "no"); + fflush(stdout); +#endif // DEBUG_PFD + if (!pixelformat) return 0; g = new Fl_Gl_Choice(m, alistp, first);