From 4729bd0fa88e6b1eebeefb996ae18d1aed11805e Mon Sep 17 00:00:00 2001
From: Stephen T <xxlennygamerxx@gmail.com>
Date: Fri, 31 Jan 2025 02:35:12 -0600
Subject: [PATCH] Port over SDL_RenderFIllRoundedRect from SDL3 renderer.
---
renderers/SDL2/clay_renderer_SDL2.c | 113 +++++++++++++++++++++++++++-
1 file changed, 112 insertions(+), 1 deletion(-)
diff --git a/renderers/SDL2/clay_renderer_SDL2.c b/renderers/SDL2/clay_renderer_SDL2.c
index 811c6ef..b1a80cc 100644
--- a/renderers/SDL2/clay_renderer_SDL2.c
+++ b/renderers/SDL2/clay_renderer_SDL2.c
@@ -33,6 +33,112 @@ static Clay_Dimensions SDL2_MeasureText(Clay_StringSlice text, Clay_TextElementC
};
}
+/* Global for convenience. Even in 4K this is enough for smooth curves (low radius or rect size coupled with
+ * no AA or low resolution might make it appear as jagged curves) */
+static int NUM_CIRCLE_SEGMENTS = 16;
+
+//all rendering is performed by a single SDL call, avoiding multiple RenderRect + plumbing choice for circles.
+static void SDL_RenderFillRoundedRect(SDL_Renderer* renderer, const SDL_FRect rect, const float cornerRadius, const Clay_Color _color) {
+ const SDL_Color color = { (Uint8)(_color.r), (Uint8)(_color.g), (Uint8)(_color.b), (Uint8)(_color.a), };
+
+ int indexCount = 0, vertexCount = 0;
+
+ const float minRadius = SDL_min(rect.w, rect.h) / 2.0f;
+ const float clampedRadius = SDL_min(cornerRadius, minRadius);
+
+ const int numCircleSegments = SDL_max(NUM_CIRCLE_SEGMENTS, (int)clampedRadius * 0.5f);
+
+ int totalVertices = 4 + (4 * (numCircleSegments * 2)) + 2 * 4;
+ int totalIndices = 6 + (4 * (numCircleSegments * 3)) + 6 * 4;
+
+ SDL_Vertex vertices[totalVertices];
+ int indices[totalIndices];
+
+ //define center rectangle
+ vertices[vertexCount++] = (SDL_Vertex){ {rect.x + clampedRadius, rect.y + clampedRadius}, color, {0, 0} }; //0 center TL
+ vertices[vertexCount++] = (SDL_Vertex){ {rect.x + rect.w - clampedRadius, rect.y + clampedRadius}, color, {1, 0} }; //1 center TR
+ vertices[vertexCount++] = (SDL_Vertex){ {rect.x + rect.w - clampedRadius, rect.y + rect.h - clampedRadius}, color, {1, 1} }; //2 center BR
+ vertices[vertexCount++] = (SDL_Vertex){ {rect.x + clampedRadius, rect.y + rect.h - clampedRadius}, color, {0, 1} }; //3 center BL
+
+ indices[indexCount++] = 0;
+ indices[indexCount++] = 1;
+ indices[indexCount++] = 3;
+ indices[indexCount++] = 1;
+ indices[indexCount++] = 2;
+ indices[indexCount++] = 3;
+
+ //define rounded corners as triangle fans
+ const float step = (M_PI / 2) / numCircleSegments;
+ for (int i = 0; i < numCircleSegments; i++) {
+ const float angle1 = (float)i * step;
+ const float angle2 = ((float)i + 1.0f) * step;
+
+ for (int j = 0; j < 4; j++) { // Iterate over four corners
+ float cx, cy, signX, signY;
+
+ switch (j) {
+ case 0: cx = rect.x + clampedRadius; cy = rect.y + clampedRadius; signX = -1; signY = -1; break; // Top-left
+ case 1: cx = rect.x + rect.w - clampedRadius; cy = rect.y + clampedRadius; signX = 1; signY = -1; break; // Top-right
+ case 2: cx = rect.x + rect.w - clampedRadius; cy = rect.y + rect.h - clampedRadius; signX = 1; signY = 1; break; // Bottom-right
+ case 3: cx = rect.x + clampedRadius; cy = rect.y + rect.h - clampedRadius; signX = -1; signY = 1; break; // Bottom-left
+ default: return;
+ }
+
+ vertices[vertexCount++] = (SDL_Vertex){ {cx + SDL_cosf(angle1) * clampedRadius * signX, cy + SDL_sinf(angle1) * clampedRadius * signY}, color, {0, 0} };
+ vertices[vertexCount++] = (SDL_Vertex){ {cx + SDL_cosf(angle2) * clampedRadius * signX, cy + SDL_sinf(angle2) * clampedRadius * signY}, color, {0, 0} };
+
+ indices[indexCount++] = j; // Connect to corresponding central rectangle vertex
+ indices[indexCount++] = vertexCount - 2;
+ indices[indexCount++] = vertexCount - 1;
+ }
+ }
+
+ //Define edge rectangles
+ // Top edge
+ vertices[vertexCount++] = (SDL_Vertex){ {rect.x + clampedRadius, rect.y}, color, {0, 0} }; //TL
+ vertices[vertexCount++] = (SDL_Vertex){ {rect.x + rect.w - clampedRadius, rect.y}, color, {1, 0} }; //TR
+
+ indices[indexCount++] = 0;
+ indices[indexCount++] = vertexCount - 2; //TL
+ indices[indexCount++] = vertexCount - 1; //TR
+ indices[indexCount++] = 1;
+ indices[indexCount++] = 0;
+ indices[indexCount++] = vertexCount - 1; //TR
+ // Right edge
+ vertices[vertexCount++] = (SDL_Vertex){ {rect.x + rect.w, rect.y + clampedRadius}, color, {1, 0} }; //RT
+ vertices[vertexCount++] = (SDL_Vertex){ {rect.x + rect.w, rect.y + rect.h - clampedRadius}, color, {1, 1} }; //RB
+
+ indices[indexCount++] = 1;
+ indices[indexCount++] = vertexCount - 2; //RT
+ indices[indexCount++] = vertexCount - 1; //RB
+ indices[indexCount++] = 2;
+ indices[indexCount++] = 1;
+ indices[indexCount++] = vertexCount - 1; //RB
+ // Bottom edge
+ vertices[vertexCount++] = (SDL_Vertex){ {rect.x + rect.w - clampedRadius, rect.y + rect.h}, color, {1, 1} }; //BR
+ vertices[vertexCount++] = (SDL_Vertex){ {rect.x + clampedRadius, rect.y + rect.h}, color, {0, 1} }; //BL
+
+ indices[indexCount++] = 2;
+ indices[indexCount++] = vertexCount - 2; //BR
+ indices[indexCount++] = vertexCount - 1; //BL
+ indices[indexCount++] = 3;
+ indices[indexCount++] = 2;
+ indices[indexCount++] = vertexCount - 1; //BL
+ // Left edge
+ vertices[vertexCount++] = (SDL_Vertex){ {rect.x, rect.y + rect.h - clampedRadius}, color, {0, 1} }; //LB
+ vertices[vertexCount++] = (SDL_Vertex){ {rect.x, rect.y + clampedRadius}, color, {0, 0} }; //LT
+
+ indices[indexCount++] = 3;
+ indices[indexCount++] = vertexCount - 2; //LB
+ indices[indexCount++] = vertexCount - 1; //LT
+ indices[indexCount++] = 0;
+ indices[indexCount++] = 3;
+ indices[indexCount++] = vertexCount - 1; //LT
+
+ // Render everything
+ SDL_RenderGeometry(renderer, NULL, vertices, vertexCount, indices, indexCount);
+}
+
SDL_Rect currentClippingRectangle;
static void Clay_SDL2_Render(SDL_Renderer *renderer, Clay_RenderCommandArray renderCommands, SDL2_Font *fonts)
@@ -53,7 +159,12 @@ static void Clay_SDL2_Render(SDL_Renderer *renderer, Clay_RenderCommandArray ren
.w = boundingBox.width,
.h = boundingBox.height,
};
- SDL_RenderFillRectF(renderer, &rect);
+ if (config->cornerRadius.topLeft > 0) {
+ SDL_RenderFillRoundedRect(renderer, rect, config->cornerRadius.topLeft, color);
+ }
+ else {
+ SDL_RenderFillRectF(renderer, &rect);
+ }
break;
}
case CLAY_RENDER_COMMAND_TYPE_TEXT: {