[Renderers/SDL3] Add image rendering and scissor support to SDL3 rend…

…erer (#246)
nicbarker · Feb 12, 2025 · bc2548e · bc2548e
1 parent eeb4520
commit bc2548e
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Showing 5 changed files with 46 additions and 6 deletions.
diff --git a/examples/SDL3-simple-demo/CMakeLists.txt b/examples/SDL3-simple-demo/CMakeLists.txt
@@ -14,7 +14,7 @@ set(FETCHCONTENT_QUIET FALSE)
 FetchContent_Declare(
 	SDL
 	GIT_REPOSITORY https://github.com/libsdl-org/SDL.git
-	GIT_TAG preview-3.1.6
+	GIT_TAG release-3.2.4
 	GIT_SHALLOW TRUE
 	GIT_PROGRESS TRUE
 )
@@ -34,11 +34,24 @@ message(STATUS "Using SDL_ttf via FetchContent")
 FetchContent_MakeAvailable(SDL_ttf)
 set_property(DIRECTORY "${sdl_ttf_SOURCE_DIR}" PROPERTY EXCLUDE_FROM_ALL TRUE)
 
+# Download SDL_image
+FetchContent_Declare(
+	SDL_image
+	GIT_REPOSITORY "https://github.com/libsdl-org/SDL_image.git"
+	GIT_TAG release-3.2.0 # Slightly risky to use main branch, but it's the only one available
+	GIT_SHALLOW TRUE
+	GIT_PROGRESS TRUE
+)
+message(STATUS "Using SDL_image via FetchContent")
+FetchContent_MakeAvailable(SDL_image)
+set_property(DIRECTORY "${SDL_image_SOURCE_DIR}" PROPERTY EXCLUDE_FROM_ALL TRUE)
+
 # Example executable
 add_executable(${PROJECT_NAME} main.c)
 target_link_libraries(${PROJECT_NAME} PRIVATE
 	SDL3::SDL3
 	SDL3_ttf::SDL3_ttf
+	SDL3_image::SDL3_image
 )
 
 add_custom_command(

diff --git a/examples/SDL3-simple-demo/main.c b/examples/SDL3-simple-demo/main.c
@@ -23,6 +23,8 @@ typedef struct app_state {
     ClayVideoDemo_Data demoData;
 } AppState;
 
+SDL_Surface *sample_image;
+
 static inline Clay_Dimensions SDL_MeasureText(Clay_StringSlice text, Clay_TextElementConfig *config, void *userData)
 {
     TTF_Font **fonts = userData;
@@ -81,6 +83,8 @@ SDL_AppResult SDL_AppInit(void **appstate, int argc, char *argv[])
 
     state->rendererData.fonts[FONT_ID] = font;
 
+    sample_image = IMG_Load("resources/sample.png");
+
     /* Initialize Clay */
     uint64_t totalMemorySize = Clay_MinMemorySize();
     Clay_Arena clayMemory = (Clay_Arena) {

diff --git a/examples/SDL3-simple-demo/resources/sample.png b/examples/SDL3-simple-demo/resources/sample.png
diff --git a/renderers/SDL3/README b/renderers/SDL3/README
diff --git a/renderers/SDL3/clay_renderer_SDL3.c b/renderers/SDL3/clay_renderer_SDL3.c
@@ -2,6 +2,7 @@
 #include <SDL3/SDL_main.h>
 #include <SDL3/SDL.h>
 #include <SDL3_ttf/SDL_ttf.h>
+#include <SDL3_image/SDL_image.h>
 
 typedef struct {
     SDL_Renderer *renderer;
@@ -140,12 +141,14 @@ static void SDL_Clay_RenderArc(Clay_SDL3RendererData *rendererData, const SDL_FP
     }
 }
 
+SDL_Rect currentClippingRectangle;
+
 static void SDL_Clay_RenderClayCommands(Clay_SDL3RendererData *rendererData, Clay_RenderCommandArray *rcommands)
 {
     for (size_t i = 0; i < rcommands->length; i++) {
         Clay_RenderCommand *rcmd = Clay_RenderCommandArray_Get(rcommands, i);
         const Clay_BoundingBox bounding_box = rcmd->boundingBox;
-        const SDL_FRect rect = { bounding_box.x, bounding_box.y, bounding_box.width, bounding_box.height };
+        const SDL_FRect rect = { (int)bounding_box.x, (int)bounding_box.y, (int)bounding_box.width, (int)bounding_box.height };
 
         switch (rcmd->commandType) {
             case CLAY_RENDER_COMMAND_TYPE_RECTANGLE: {
@@ -231,6 +234,30 @@ static void SDL_Clay_RenderClayCommands(Clay_SDL3RendererData *rendererData, Cla
                 }
 
             } break;
+            case CLAY_RENDER_COMMAND_TYPE_SCISSOR_START: {
+                Clay_BoundingBox boundingBox = rcmd->boundingBox;
+                currentClippingRectangle = (SDL_Rect) {
+                        .x = boundingBox.x,
+                        .y = boundingBox.y,
+                        .w = boundingBox.width,
+                        .h = boundingBox.height,
+                };
+                SDL_SetRenderClipRect(rendererData->renderer, &currentClippingRectangle);
+                break;
+            }
+            case CLAY_RENDER_COMMAND_TYPE_SCISSOR_END: {
+                SDL_SetRenderClipRect(rendererData->renderer, NULL);
+                break;
+            }
+            case CLAY_RENDER_COMMAND_TYPE_IMAGE: {
+                SDL_Surface *image = (SDL_Surface *)rcmd->renderData.image.imageData;
+                SDL_Texture *texture = SDL_CreateTextureFromSurface(rendererData->renderer, image);
+                const SDL_FRect dest = { rect.x, rect.y, rect.w, rect.h };
+
+                SDL_RenderTexture(rendererData->renderer, texture, NULL, &dest);
+                SDL_DestroyTexture(texture);
+                break;
+            }
             default:
                 SDL_Log("Unknown render command type: %d", rcmd->commandType);
         }