From eb553962e8c35dd81db0607414fb46ad321e6400 Mon Sep 17 00:00:00 2001
From: Timothy Hoyt <72295021+TimothyHoytBSME@users.noreply.github.com>
Date: Thu, 13 Feb 2025 15:14:11 -0600
Subject: [PATCH] [Renderers/SDL2] Added rounded corner borders and fixed other
issues (#258)
---
renderers/SDL2/clay_renderer_SDL2.c | 210 ++++++++++++++++++++++++----
1 file changed, 184 insertions(+), 26 deletions(-)
diff --git a/renderers/SDL2/clay_renderer_SDL2.c b/renderers/SDL2/clay_renderer_SDL2.c
index 088bf5b..1fed40c 100644
--- a/renderers/SDL2/clay_renderer_SDL2.c
+++ b/renderers/SDL2/clay_renderer_SDL2.c
@@ -4,6 +4,10 @@
#include <SDL_image.h>
#include <stdio.h>
+#ifndef M_PI
+ #define M_PI 3.14159
+#endif
+
#define CLAY_COLOR_TO_SDL_COLOR_ARGS(color) color.r, color.g, color.b, color.a
typedef struct
@@ -48,8 +52,8 @@ static void SDL_RenderFillRoundedRect(SDL_Renderer* renderer, const SDL_FRect re
int indexCount = 0, vertexCount = 0;
- const float minRadius = SDL_min(rect.w, rect.h) / 2.0f;
- const float clampedRadius = SDL_min(cornerRadius, minRadius);
+ const float maxRadius = SDL_min(rect.w, rect.h) / 2.0f;
+ const float clampedRadius = SDL_min(cornerRadius, maxRadius);
const int numCircleSegments = SDL_max(NUM_CIRCLE_SEGMENTS, (int)clampedRadius * 0.5f);
@@ -141,6 +145,121 @@ static void SDL_RenderFillRoundedRect(SDL_Renderer* renderer, const SDL_FRect re
SDL_RenderGeometry(renderer, NULL, vertices, vertexCount, indices, indexCount);
}
+//all rendering is performed by a single SDL call, using twi sets of arcing triangles, inner and outer, that fit together; along with two tringles to fill the end gaps.
+void SDL_RenderCornerBorder(SDL_Renderer *renderer, Clay_BoundingBox* boundingBox, Clay_BorderRenderData* config, int cornerIndex, Clay_Color _color){
+ /////////////////////////////////
+ //The arc is constructed of outer triangles and inner triangles (if needed).
+ //First three vertices are first outer triangle's vertices
+ //Each two vertices after that are the inner-middle and second-outer vertex of
+ //each outer triangle after the first, because there first-outer vertex is equal to the
+ //second-outer vertex of the previous triangle. Indices set accordingly.
+ //The final two vertices are the missing vertices for the first and last inner triangles (if needed)
+ //Everything is in clockwise order (CW).
+ /////////////////////////////////
+ const SDL_Color color = (SDL_Color) {
+ .r = (Uint8)_color.r,
+ .g = (Uint8)_color.g,
+ .b = (Uint8)_color.b,
+ .a = (Uint8)_color.a,
+ };
+
+ float centerX, centerY, outerRadius, clampedRadius, startAngle, borderWidth;
+ const float maxRadius = SDL_min(boundingBox->width, boundingBox->height) / 2.0f;
+
+ SDL_Vertex vertices[512];
+ int indices[512];
+ int indexCount = 0, vertexCount = 0;
+
+ switch (cornerIndex) {
+ case(0):
+ startAngle = M_PI;
+ outerRadius = SDL_min(config->cornerRadius.topLeft, maxRadius);
+ centerX = boundingBox->x + outerRadius;
+ centerY = boundingBox->y + outerRadius;
+ borderWidth = config->width.top;
+ break;
+ case(1):
+ startAngle = 3*M_PI/2;
+ outerRadius = SDL_min(config->cornerRadius.topRight, maxRadius);
+ centerX = boundingBox->x + boundingBox->width - outerRadius;
+ centerY = boundingBox->y + outerRadius;
+ borderWidth = config->width.top;
+ break;
+ case(2):
+ startAngle = 0;
+ outerRadius = SDL_min(config->cornerRadius.bottomRight, maxRadius);
+ centerX = boundingBox->x + boundingBox->width - outerRadius;
+ centerY = boundingBox->y + boundingBox->height - outerRadius;
+ borderWidth = config->width.bottom;
+ break;
+ case(3):
+ startAngle = M_PI/2;
+ outerRadius = SDL_min(config->cornerRadius.bottomLeft, maxRadius);
+ centerX = boundingBox->x + outerRadius;
+ centerY = boundingBox->y + boundingBox->height - outerRadius;
+ borderWidth = config->width.bottom;
+ break;
+ default: break;
+ }
+
+ const float innerRadius = outerRadius - borderWidth;
+ const int minNumOuterTriangles = NUM_CIRCLE_SEGMENTS;
+ const int numOuterTriangles = SDL_max(minNumOuterTriangles, ceilf(outerRadius * 0.5f));
+ const float angleStep = M_PI / (2.0*(float)numOuterTriangles);
+
+ //outer triangles, in CW order
+ for (int i = 0; i < numOuterTriangles; i++) {
+ float angle1 = startAngle + i*angleStep; //first-outer vertex angle
+ float angle2 = startAngle + ((float)i + 0.5) * angleStep; //inner-middle vertex angle
+ float angle3 = startAngle + (i+1)*angleStep; // second-outer vertex angle
+
+ if( i == 0){ //first outer triangle
+ vertices[vertexCount++] = (SDL_Vertex){ {centerX + SDL_cosf(angle1) * outerRadius, centerY + SDL_sinf(angle1) * outerRadius}, color, {0, 0} }; //vertex index = 0
+ }
+ indices[indexCount++] = vertexCount - 1; //will be second-outer vertex of last outer triangle if not first outer triangle.
+
+ vertices[vertexCount++] = (innerRadius > 0)?
+ (SDL_Vertex){ {centerX + SDL_cosf(angle2) * (innerRadius), centerY + SDL_sinf(angle2) * (innerRadius)}, color, {0, 0}}:
+ (SDL_Vertex){ {centerX, centerY }, color, {0, 0}};
+ indices[indexCount++] = vertexCount - 1;
+
+ vertices[vertexCount++] = (SDL_Vertex){ {centerX + SDL_cosf(angle3) * outerRadius, centerY + SDL_sinf(angle3) * outerRadius}, color, {0, 0} };
+ indices[indexCount++] = vertexCount - 1;
+ }
+
+ if(innerRadius > 0){
+ // inner triangles in CW order (except the first and last)
+ for (int i = 0; i < numOuterTriangles - 1; i++){ //skip the last outer triangle
+ if(i==0){ //first outer triangle -> second inner triangle
+ indices[indexCount++] = 1; //inner-middle vertex of first outer triangle
+ indices[indexCount++] = 2; //second-outer vertex of first outer triangle
+ indices[indexCount++] = 3; //innder-middle vertex of second-outer triangle
+ }else{
+ int baseIndex = 3; //skip first outer triangle
+ indices[indexCount++] = baseIndex + (i-1)*2; // inner-middle vertex of current outer triangle
+ indices[indexCount++] = baseIndex + (i-1)*2 + 1; // second-outer vertex of current outer triangle
+ indices[indexCount++] = baseIndex + (i-1)*2 + 2; // inner-middle vertex of next outer triangle
+ }
+ }
+
+ float endAngle = startAngle + M_PI/2.0;
+
+ //last inner triangle
+ indices[indexCount++] = vertexCount - 2; //inner-middle vertex of last outer triangle
+ indices[indexCount++] = vertexCount - 1; //second-outer vertex of last outer triangle
+ vertices[vertexCount++] = (SDL_Vertex){ {centerX + SDL_cosf(endAngle) * innerRadius, centerY + SDL_sinf(endAngle) * innerRadius}, color, {0, 0} }; //missing vertex
+ indices[indexCount++] = vertexCount - 1;
+
+ // //first inner triangle
+ indices[indexCount++] = 0; //first-outer vertex of first outer triangle
+ indices[indexCount++] = 1; //inner-middle vertex of first outer triangle
+ vertices[vertexCount++] = (SDL_Vertex){ {centerX + SDL_cosf(startAngle) * innerRadius, centerY + SDL_sinf(startAngle) * innerRadius}, color, {0, 0} }; //missing vertex
+ indices[indexCount++] = vertexCount - 1;
+ }
+
+ 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)
@@ -228,35 +347,74 @@ static void Clay_SDL2_Render(SDL_Renderer *renderer, Clay_RenderCommandArray ren
}
case CLAY_RENDER_COMMAND_TYPE_BORDER: {
Clay_BorderRenderData *config = &renderCommand->renderData.border;
+ SDL_SetRenderDrawColor(renderer, CLAY_COLOR_TO_SDL_COLOR_ARGS(config->color));
- if (config->width.left > 0) {
- SDL_SetRenderDrawColor(renderer, CLAY_COLOR_TO_SDL_COLOR_ARGS(config->color));
- SDL_FRect rect = { boundingBox.x, boundingBox.y + config->cornerRadius.topLeft, config->width.left, boundingBox.height - config->cornerRadius.topLeft - config->cornerRadius.bottomLeft };
- SDL_RenderFillRectF(renderer, &rect);
- }
+ if(boundingBox.width > 0 & boundingBox.height > 0){
+ const float maxRadius = SDL_min(boundingBox.width, boundingBox.height) / 2.0f;
- if (config->width.right > 0) {
- SDL_SetRenderDrawColor(renderer, CLAY_COLOR_TO_SDL_COLOR_ARGS(config->color));
- SDL_FRect rect = { boundingBox.x + boundingBox.width - config->width.right, boundingBox.y + config->cornerRadius.topRight, config->width.right, boundingBox.height - config->cornerRadius.topRight - config->cornerRadius.bottomRight };
- SDL_RenderFillRectF(renderer, &rect);
- }
+ if (config->width.left > 0) {
+ const float clampedRadiusTop = SDL_min((float)config->cornerRadius.topLeft, maxRadius);
+ const float clampedRadiusBottom = SDL_min((float)config->cornerRadius.bottomLeft, maxRadius);
+ SDL_FRect rect = {
+ boundingBox.x,
+ boundingBox.y + clampedRadiusTop,
+ (float)config->width.left,
+ (float)boundingBox.height - clampedRadiusTop - clampedRadiusBottom
+ };
+ SDL_RenderFillRectF(renderer, &rect);
+ }
+
+ if (config->width.right > 0) {
+ const float clampedRadiusTop = SDL_min((float)config->cornerRadius.topRight, maxRadius);
+ const float clampedRadiusBottom = SDL_min((float)config->cornerRadius.bottomRight, maxRadius);
+ SDL_FRect rect = {
+ boundingBox.x + boundingBox.width - config->width.right,
+ boundingBox.y + clampedRadiusTop,
+ (float)config->width.right,
+ (float)boundingBox.height - clampedRadiusTop - clampedRadiusBottom
+ };
+ SDL_RenderFillRectF(renderer, &rect);
+ }
+
+ if (config->width.top > 0) {
+ const float clampedRadiusLeft = SDL_min((float)config->cornerRadius.topLeft, maxRadius);
+ const float clampedRadiusRight = SDL_min((float)config->cornerRadius.topRight, maxRadius);
+ SDL_FRect rect = {
+ boundingBox.x + clampedRadiusLeft,
+ boundingBox.y,
+ boundingBox.width - clampedRadiusLeft - clampedRadiusRight,
+ (float)config->width.top };
+ SDL_RenderFillRectF(renderer, &rect);
+ }
+
+ if (config->width.bottom > 0) {
+ const float clampedRadiusLeft = SDL_min((float)config->cornerRadius.bottomLeft, maxRadius);
+ const float clampedRadiusRight = SDL_min((float)config->cornerRadius.bottomRight, maxRadius);
+ SDL_FRect rect = {
+ boundingBox.x + clampedRadiusLeft,
+ boundingBox.y + boundingBox.height - config->width.bottom,
+ boundingBox.width - clampedRadiusLeft - clampedRadiusRight,
+ (float)config->width.bottom
+ };
+ SDL_RenderFillRectF(renderer, &rect);
+ }
+
+ //corner index: 0->3 topLeft -> CW -> bottonLeft
+ if (config->width.top > 0 & config->cornerRadius.topLeft > 0) {
+ SDL_RenderCornerBorder(renderer, &boundingBox, config, 0, config->color);
+ }
- if (config->width.right > 0) {
- SDL_SetRenderDrawColor(renderer, CLAY_COLOR_TO_SDL_COLOR_ARGS(config->color));
- SDL_FRect rect = { boundingBox.x + boundingBox.width - config->width.right, boundingBox.y + config->cornerRadius.topRight, config->width.right, boundingBox.height - config->cornerRadius.topRight - config->cornerRadius.bottomRight };
- SDL_RenderFillRectF(renderer, &rect);
- }
+ if (config->width.top > 0 & config->cornerRadius.topRight> 0) {
+ SDL_RenderCornerBorder(renderer, &boundingBox, config, 1, config->color);
+ }
- if (config->width.top > 0) {
- SDL_SetRenderDrawColor(renderer, CLAY_COLOR_TO_SDL_COLOR_ARGS(config->color));
- SDL_FRect rect = { boundingBox.x + config->cornerRadius.topLeft, boundingBox.y, boundingBox.width - config->cornerRadius.topLeft - config->cornerRadius.topRight, config->width.top };
- SDL_RenderFillRectF(renderer, &rect);
- }
+ if (config->width.bottom > 0 & config->cornerRadius.bottomLeft > 0) {
+ SDL_RenderCornerBorder(renderer, &boundingBox, config, 2, config->color);
+ }
- if (config->width.bottom > 0) {
- SDL_SetRenderDrawColor(renderer, CLAY_COLOR_TO_SDL_COLOR_ARGS(config->color));
- SDL_FRect rect = { boundingBox.x + config->cornerRadius.bottomLeft, boundingBox.y + boundingBox.height - config->width.bottom, boundingBox.width - config->cornerRadius.bottomLeft - config->cornerRadius.bottomRight, config->width.bottom };
- SDL_RenderFillRectF(renderer, &rect);
+ if (config->width.bottom > 0 & config->cornerRadius.bottomLeft > 0) {
+ SDL_RenderCornerBorder(renderer, &boundingBox, config, 3, config->color);
+ }
}
break;