game-dev/clay/clay_renderer_SDL3.c

266 lines
14 KiB
C

#include "clay.h"
#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;
TTF_TextEngine *textEngine;
TTF_Font **fonts;
} Clay_SDL3RendererData;
/* 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_Clay_RenderFillRoundedRect(Clay_SDL3RendererData *rendererData, const SDL_FRect rect, const float cornerRadius, const Clay_Color _color) {
const SDL_FColor color = { _color.r/255, _color.g/255, _color.b/255, _color.a/255 };
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 = (SDL_PI_F/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(rendererData->renderer, NULL, vertices, vertexCount, indices, indexCount);
}
static void SDL_Clay_RenderArc(Clay_SDL3RendererData *rendererData, const SDL_FPoint center, const float radius, const float startAngle, const float endAngle, const float thickness, const Clay_Color color) {
SDL_SetRenderDrawColor(rendererData->renderer, color.r, color.g, color.b, color.a);
const float radStart = startAngle * (SDL_PI_F / 180.0f);
const float radEnd = endAngle * (SDL_PI_F / 180.0f);
const int numCircleSegments = SDL_max(NUM_CIRCLE_SEGMENTS, (int)(radius * 1.5f)); //increase circle segments for larger circles, 1.5 is arbitrary.
const float angleStep = (radEnd - radStart) / (float)numCircleSegments;
const float thicknessStep = 0.4f; //arbitrary value to avoid overlapping lines. Changing THICKNESS_STEP or numCircleSegments might cause artifacts.
for (float t = thicknessStep; t < thickness - thicknessStep; t += thicknessStep) {
SDL_FPoint points[numCircleSegments + 1];
const float clampedRadius = SDL_max(radius - t, 1.0f);
for (int i = 0; i <= numCircleSegments; i++) {
const float angle = radStart + i * angleStep;
points[i] = (SDL_FPoint){
SDL_roundf(center.x + SDL_cosf(angle) * clampedRadius),
SDL_roundf(center.y + SDL_sinf(angle) * clampedRadius) };
}
SDL_RenderLines(rendererData->renderer, points, numCircleSegments + 1);
}
}
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 = { (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: {
Clay_RectangleRenderData *config = &rcmd->renderData.rectangle;
SDL_SetRenderDrawBlendMode(rendererData->renderer, SDL_BLENDMODE_BLEND);
SDL_SetRenderDrawColor(rendererData->renderer, config->backgroundColor.r, config->backgroundColor.g, config->backgroundColor.b, config->backgroundColor.a);
if (config->cornerRadius.topLeft > 0) {
SDL_Clay_RenderFillRoundedRect(rendererData, rect, config->cornerRadius.topLeft, config->backgroundColor);
} else {
SDL_RenderFillRect(rendererData->renderer, &rect);
}
} break;
case CLAY_RENDER_COMMAND_TYPE_TEXT: {
Clay_TextRenderData *config = &rcmd->renderData.text;
TTF_Font *font = rendererData->fonts[config->fontId];
TTF_Text *text = TTF_CreateText(rendererData->textEngine, font, config->stringContents.chars, config->stringContents.length);
TTF_SetTextColor(text, config->textColor.r, config->textColor.g, config->textColor.b, config->textColor.a);
TTF_DrawRendererText(text, rect.x, rect.y);
TTF_DestroyText(text);
} break;
case CLAY_RENDER_COMMAND_TYPE_BORDER: {
Clay_BorderRenderData *config = &rcmd->renderData.border;
const float minRadius = SDL_min(rect.w, rect.h) / 2.0f;
const Clay_CornerRadius clampedRadii = {
.topLeft = SDL_min(config->cornerRadius.topLeft, minRadius),
.topRight = SDL_min(config->cornerRadius.topRight, minRadius),
.bottomLeft = SDL_min(config->cornerRadius.bottomLeft, minRadius),
.bottomRight = SDL_min(config->cornerRadius.bottomRight, minRadius)
};
//edges
SDL_SetRenderDrawColor(rendererData->renderer, config->color.r, config->color.g, config->color.b, config->color.a);
if (config->width.left > 0) {
const float starting_y = rect.y + clampedRadii.topLeft;
const float length = rect.h - clampedRadii.topLeft - clampedRadii.bottomLeft;
SDL_FRect line = { rect.x, starting_y, config->width.left, length };
SDL_RenderFillRect(rendererData->renderer, &line);
}
if (config->width.right > 0) {
const float starting_x = rect.x + rect.w - (float)config->width.right;
const float starting_y = rect.y + clampedRadii.topRight;
const float length = rect.h - clampedRadii.topRight - clampedRadii.bottomRight;
SDL_FRect line = { starting_x, starting_y, config->width.right, length };
SDL_RenderFillRect(rendererData->renderer, &line);
}
if (config->width.top > 0) {
const float starting_x = rect.x + clampedRadii.topLeft;
const float length = rect.w - clampedRadii.topLeft - clampedRadii.topRight;
SDL_FRect line = { starting_x, rect.y, length, config->width.top };
SDL_RenderFillRect(rendererData->renderer, &line);
}
if (config->width.bottom > 0) {
const float starting_x = rect.x + clampedRadii.bottomLeft;
const float starting_y = rect.y + rect.h - (float)config->width.bottom;
const float length = rect.w - clampedRadii.bottomLeft - clampedRadii.bottomRight;
SDL_FRect line = { starting_x, starting_y, length, config->width.bottom };
SDL_SetRenderDrawColor(rendererData->renderer, config->color.r, config->color.g, config->color.b, config->color.a);
SDL_RenderFillRect(rendererData->renderer, &line);
}
//corners
if (config->cornerRadius.topLeft > 0) {
const float centerX = rect.x + clampedRadii.topLeft -1;
const float centerY = rect.y + clampedRadii.topLeft;
SDL_Clay_RenderArc(rendererData, (SDL_FPoint){centerX, centerY}, clampedRadii.topLeft,
180.0f, 270.0f, config->width.top, config->color);
}
if (config->cornerRadius.topRight > 0) {
const float centerX = rect.x + rect.w - clampedRadii.topRight -1;
const float centerY = rect.y + clampedRadii.topRight;
SDL_Clay_RenderArc(rendererData, (SDL_FPoint){centerX, centerY}, clampedRadii.topRight,
270.0f, 360.0f, config->width.top, config->color);
}
if (config->cornerRadius.bottomLeft > 0) {
const float centerX = rect.x + clampedRadii.bottomLeft -1;
const float centerY = rect.y + rect.h - clampedRadii.bottomLeft -1;
SDL_Clay_RenderArc(rendererData, (SDL_FPoint){centerX, centerY}, clampedRadii.bottomLeft,
90.0f, 180.0f, config->width.bottom, config->color);
}
if (config->cornerRadius.bottomRight > 0) {
const float centerX = rect.x + rect.w - clampedRadii.bottomRight -1; //TODO: why need to -1 in all calculations???
const float centerY = rect.y + rect.h - clampedRadii.bottomRight -1;
SDL_Clay_RenderArc(rendererData, (SDL_FPoint){centerX, centerY}, clampedRadii.bottomRight,
0.0f, 90.0f, config->width.bottom, config->color);
}
} 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);
}
}
}