WIP Backends: SDLRenderer3: transform vertices manually.

This commit is contained in:
ocornut 2024-05-15 15:49:14 +02:00
parent 61f07d099c
commit b02532f0a7

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@ -51,7 +51,8 @@ struct ImGui_ImplSDLRenderer3_Data
{
SDL_Renderer* Renderer; // Main viewport's renderer
SDL_Texture* FontTexture;
ImVector<SDL_FColor> ColorBuffer;
ImVector<SDL_FColor> ColorBuffer; // Transformed color buffer
ImVector<ImVec2> PosBuffer; // Transformed pos buffer (for multi-viewports only)
ImGui_ImplSDLRenderer3_Data() { memset((void*)this, 0, sizeof(*this)); }
};
@ -214,13 +215,32 @@ void ImGui_ImplSDLRenderer3_RenderDrawData(ImDrawData* draw_data, SDL_Renderer*
SDL_SetRenderClipRect(renderer, &r);
const float* xy = (const float*)(const void*)((const char*)(vtx_buffer + pcmd->VtxOffset) + offsetof(ImDrawVert, pos));
int xy_stride = (int)sizeof(ImDrawVert);
const float* uv = (const float*)(const void*)((const char*)(vtx_buffer + pcmd->VtxOffset) + offsetof(ImDrawVert, uv));
const SDL_Color* color = (const SDL_Color*)(const void*)((const char*)(vtx_buffer + pcmd->VtxOffset) + offsetof(ImDrawVert, col)); // SDL 2.0.19+
// FIXME-OPT: Transform position manually
// FIXME-OPT: Note that SDL_RenderGeometryRaw() does another transform for colors..
if (draw_data->DisplayPos.x != 0.0f || draw_data->DisplayPos.y != 0.0f)
{
const float off_x = draw_data->DisplayPos.x;
const float off_y = draw_data->DisplayPos.y;
bd->PosBuffer.resize(pcmd->ElemCount);
const ImDrawVert* p_in = vtx_buffer + pcmd->VtxOffset;
ImVec2* p_out = bd->PosBuffer.Data;
for (int remaining = pcmd->ElemCount; remaining > 0; remaining--, p_out++, p_in++)
{
p_out->x = p_in->pos.x - off_x;
p_out->y = p_in->pos.y - off_y;
}
xy = (const float*)bd->PosBuffer.Data;
xy_stride = (int)sizeof(ImVec2);
}
// Bind texture, Draw
SDL_Texture* tex = (SDL_Texture*)pcmd->GetTexID();
SDL_RenderGeometryRaw8BitColor(renderer, bd->ColorBuffer, tex,
xy, (int)sizeof(ImDrawVert),
xy, xy_stride,
color, (int)sizeof(ImDrawVert),
uv, (int)sizeof(ImDrawVert),
cmd_list->VtxBuffer.Size - pcmd->VtxOffset,