diff --git a/backends/imgui_impl_sdlsurface2.cpp b/backends/imgui_impl_sdlsurface2.cpp index c6e27a651..d432a2f2b 100644 --- a/backends/imgui_impl_sdlsurface2.cpp +++ b/backends/imgui_impl_sdlsurface2.cpp @@ -10,14 +10,70 @@ static SDL_Surface* g_TargetSurface = nullptr; static SDL_Surface* g_FontSurface = nullptr; -static inline void PutPixel(SDL_Surface* surface, int x, int y, Uint8 r, Uint8 g, Uint8 b, Uint8 a) +static inline Uint32 GetPixel(SDL_Surface* s, int x, int y) { - if (x < 0 || y < 0 || x >= surface->w || y >= surface->h) return; - Uint32 pixel = SDL_MapRGBA(surface->format, r, g, b, a); - Uint8* pixels = (Uint8*)surface->pixels; - int pitch = surface->pitch; - Uint32* dst = (Uint32*)(pixels + y * pitch + x * 4); - *dst = pixel; + Uint8* p = (Uint8*)s->pixels + y * s->pitch + x * s->format->BytesPerPixel; + switch (s->format->BytesPerPixel) + { + case 1: return *p; + case 2: return *(Uint16*)p; + case 3: + if (SDL_BYTEORDER == SDL_BIG_ENDIAN) + return (p[0] << 16) | (p[1] << 8) | p[2]; + else + return p[0] | (p[1] << 8) | (p[2] << 16); + case 4: return *(Uint32*)p; + } + return 0; +} + +static inline void BlendPixel(SDL_Surface* s, int x, int y, + Uint8 sr, Uint8 sg, Uint8 sb, Uint8 sa) +{ + if (!s || sa == 0) return; + if (x < 0 || y < 0 || x >= s->w || y >= s->h) return; + + Uint32 dst_pix = GetPixel(s, x, y); + + Uint8 dr, dg, db, da; + SDL_GetRGBA(dst_pix, s->format, &dr, &dg, &db, &da); + + float src_a = sa / 255.0f; + float dst_a = da / 255.0f; + float out_a = src_a + dst_a * (1.0f - src_a); + + float out_r = (sr * src_a + dr * dst_a * (1.0f - src_a)) / (out_a > 0 ? out_a : 1.0f); + float out_g = (sg * src_a + dg * dst_a * (1.0f - src_a)) / (out_a > 0 ? out_a : 1.0f); + float out_b = (sb * src_a + db * dst_a * (1.0f - src_a)) / (out_a > 0 ? out_a : 1.0f); + + Uint8 fr = (Uint8)std::clamp(out_r, 0.0f, 255.0f); + Uint8 fg = (Uint8)std::clamp(out_g, 0.0f, 255.0f); + Uint8 fb = (Uint8)std::clamp(out_b, 0.0f, 255.0f); + Uint8 fa = (Uint8)std::clamp(out_a * 255.0f, 0.0f, 255.0f); + + Uint32 out_pix = SDL_MapRGBA(s->format, fr, fg, fb, fa); + + Uint8* p = (Uint8*)s->pixels + y * s->pitch + x * s->format->BytesPerPixel; + switch (s->format->BytesPerPixel) + { + case 1: *p = (Uint8)out_pix; break; + case 2: *(Uint16*)p = (Uint16)out_pix; break; + case 3: + if (SDL_BYTEORDER == SDL_BIG_ENDIAN) + { + p[0] = (out_pix >> 16) & 0xFF; + p[1] = (out_pix >> 8) & 0xFF; + p[2] = out_pix & 0xFF; + } + else + { + p[0] = out_pix & 0xFF; + p[1] = (out_pix >> 8) & 0xFF; + p[2] = (out_pix >> 16) & 0xFF; + } + break; + case 4: *(Uint32*)p = out_pix; break; + } } static inline float Edge(const ImVec2& a, const ImVec2& b, float x, float y) @@ -37,8 +93,9 @@ SDL_Surface* ImGui_ImplSDLSurface2_CreateFontAtlasSurface() if (!surf) return nullptr; SDL_LockSurface(surf); - memcpy(surf->pixels, pixels, width * height * 4); + std::memcpy(surf->pixels, pixels, width * height * 4); SDL_UnlockSurface(surf); + SDL_SetSurfaceBlendMode(surf, SDL_BLENDMODE_NONE); return surf; } @@ -91,17 +148,20 @@ void ImGui_ImplSDLSurface2_RenderDrawData(ImDrawData* draw_data) for (int cmd_i = 0; cmd_i < cmd_list->CmdBuffer.Size; cmd_i++) { const ImDrawCmd* pcmd = &cmd_list->CmdBuffer[cmd_i]; - if (pcmd->ElemCount == 0) { idx_offset += 0; continue; } + if (pcmd->ElemCount == 0) + continue; - ImVec2 clip_min = ImVec2((pcmd->ClipRect.x - display_pos.x) * fb_scale.x, - (pcmd->ClipRect.y - display_pos.y) * fb_scale.y); - ImVec2 clip_max = ImVec2((pcmd->ClipRect.z - display_pos.x) * fb_scale.x, - (pcmd->ClipRect.w - display_pos.y) * fb_scale.y); + ImVec2 clip_min = ImVec2( + (pcmd->ClipRect.x - display_pos.x) * fb_scale.x, + (pcmd->ClipRect.y - display_pos.y) * fb_scale.y); + ImVec2 clip_max = ImVec2( + (pcmd->ClipRect.z - display_pos.x) * fb_scale.x, + (pcmd->ClipRect.w - display_pos.y) * fb_scale.y); - int cx0 = (int)floor(clip_min.x); - int cy0 = (int)floor(clip_min.y); - int cx1 = (int)ceil(clip_max.x); - int cy1 = (int)ceil(clip_max.y); + int cx0 = (int)std::floor(clip_min.x); + int cy0 = (int)std::floor(clip_min.y); + int cx1 = (int)std::ceil (clip_max.x); + int cy1 = (int)std::ceil (clip_max.y); cx0 = std::max(cx0, 0); cy0 = std::max(cy0, 0); @@ -114,11 +174,7 @@ void ImGui_ImplSDLSurface2_RenderDrawData(ImDrawData* draw_data) continue; } - SDL_Rect srect; - srect.x = cx0; - srect.y = cy0; - srect.w = cx1 - cx0; - srect.h = cy1 - cy0; + SDL_Rect srect{ cx0, cy0, cx1 - cx0, cy1 - cy0 }; SDL_SetClipRect(g_TargetSurface, &srect); SDL_Surface* tex = (SDL_Surface*)pcmd->GetTexID(); @@ -137,10 +193,10 @@ void ImGui_ImplSDLSurface2_RenderDrawData(ImDrawData* draw_data) ImVec2 p1 = ImVec2((v1.pos.x - display_pos.x) * fb_scale.x, (v1.pos.y - display_pos.y) * fb_scale.y); ImVec2 p2 = ImVec2((v2.pos.x - display_pos.x) * fb_scale.x, (v2.pos.y - display_pos.y) * fb_scale.y); - int minx = (int)floor(std::min(std::min(p0.x, p1.x), p2.x)); - int miny = (int)floor(std::min(std::min(p0.y, p1.y), p2.y)); - int maxx = (int)ceil(std::max(std::max(p0.x, p1.x), p2.x)); - int maxy = (int)ceil(std::max(std::max(p0.y, p1.y), p2.y)); + int minx = (int)std::floor(std::min({ p0.x, p1.x, p2.x })); + int miny = (int)std::floor(std::min({ p0.y, p1.y, p2.y })); + int maxx = (int)std::ceil (std::max({ p0.x, p1.x, p2.x })); + int maxy = (int)std::ceil (std::max({ p0.y, p1.y, p2.y })); minx = std::max(minx, cx0); miny = std::max(miny, cy0); @@ -180,37 +236,36 @@ void ImGui_ImplSDLSurface2_RenderDrawData(ImDrawData* draw_data) float b = w0 * c0[2] + w1 * c1[2] + w2 * c2[2]; float a = w0 * c0[3] + w1 * c1[3] + w2 * c2[3]; - Uint8 out_r = (Uint8)(std::min(1.0f, r) * 255.0f); - Uint8 out_g = (Uint8)(std::min(1.0f, g) * 255.0f); - Uint8 out_b = (Uint8)(std::min(1.0f, b) * 255.0f); - Uint8 out_a = (Uint8)(std::min(1.0f, a) * 255.0f); + Uint8 out_r = (Uint8)(std::clamp(r, 0.0f, 1.0f) * 255.0f); + Uint8 out_g = (Uint8)(std::clamp(g, 0.0f, 1.0f) * 255.0f); + Uint8 out_b = (Uint8)(std::clamp(b, 0.0f, 1.0f) * 255.0f); + Uint8 out_a = (Uint8)(std::clamp(a, 0.0f, 1.0f) * 255.0f); if (tex) { - ImVec2 uv0 = v0.uv; ImVec2 uv1 = v1.uv; ImVec2 uv2 = v2.uv; + ImVec2 uv0 = v0.uv, uv1 = v1.uv, uv2 = v2.uv; float u = w0 * uv0.x + w1 * uv1.x + w2 * uv2.x; float v = w0 * uv0.y + w1 * uv1.y + w2 * uv2.y; + int tx = (int)(u * (tex->w - 1) + 0.5f); int ty = (int)(v * (tex->h - 1) + 0.5f); tx = std::clamp(tx, 0, tex->w - 1); ty = std::clamp(ty, 0, tex->h - 1); - Uint8* tpx = (Uint8*)tex->pixels + ty * tex->pitch + tx * 4; - Uint8 tr = tpx[0]; - Uint8 tg = tpx[1]; - Uint8 tb = tpx[2]; - Uint8 ta = tpx[3]; + Uint32 tpx = GetPixel(tex, tx, ty); + Uint8 tr, tg, tb, ta; + SDL_GetRGBA(tpx, tex->format, &tr, &tg, &tb, &ta); Uint8 final_r = (Uint8)((tr * out_r) / 255); Uint8 final_g = (Uint8)((tg * out_g) / 255); Uint8 final_b = (Uint8)((tb * out_b) / 255); Uint8 final_a = (Uint8)((ta * out_a) / 255); - PutPixel(g_TargetSurface, x, y, final_r, final_g, final_b, final_a); + BlendPixel(g_TargetSurface, x, y, final_r, final_g, final_b, final_a); } else { - PutPixel(g_TargetSurface, x, y, out_r, out_g, out_b, out_a); + BlendPixel(g_TargetSurface, x, y, out_r, out_g, out_b, out_a); } } }