Started work on grid creation menu

src/WorldGrid.cpp

@@ -0,0 +1,137 @@
+#include "WorldGrid.hpp"
+#include "GridManager.hpp"
+#include "MainProgram.hpp"
+
+sk_sp<SkRuntimeEffect> WorldGrid::circlePointEffect;
+sk_sp<SkRuntimeEffect> WorldGrid::squarePointEffect;
+sk_sp<SkRuntimeEffect> WorldGrid::squareLinesEffect;
+sk_sp<SkRuntimeEffect> WorldGrid::ruledEffect;
+Vector2f WorldGrid::oldWindowSize = Vector2f{0.0f, 0.0f};
+
+#define GRID_CACHE_SIZE 10.0f
+#define GRID_CACHE_SIZE_INT 10
+
+// NOTE: Skia shaders return premultiplied alpha colors
+
+const char* circlePointShaderCode = R"V(
+uniform vec4 gridColor;
+uniform float gridScale;
+
+vec4 main(float2 fragCoord) {
+    float circleRadius = min(5.0 / gridScale, 0.25);
+    float2 modCoord = mod(fragCoord + float2(5.0), float2(10.0));
+    float fin = step(distance(float2(5.0), modCoord), circleRadius);
+
+    vec4 pointColorUnmultiplied = vec4(gridColor.rgb, 1.0);
+
+  	return pointColorUnmultiplied * gridColor.a * fin;
+})V";
+
+const char* squarePointShaderCode = R"V(
+uniform vec4 gridColor;
+uniform float gridScale;
+
+vec4 main(float2 fragCoord) {
+    float squareSize = min(10.0 / gridScale, 0.5);
+    float gridUnit = 1.0 / gridScale;
+  	float m1 = step(mod(fragCoord.x + gridUnit + squareSize * 0.5, 10.0), squareSize);
+    float m2 = step(mod(fragCoord.y + gridUnit + squareSize * 0.5, 10.0), squareSize);
+    float fin = m1 * m2;
+
+    vec4 pointColorUnmultiplied = vec4(gridColor.rgb, 1.0);
+
+  	return pointColorUnmultiplied * gridColor.a * fin;
+})V";
+
+const char* squareLinesShaderCode = R"V(
+uniform vec4 gridColor;
+uniform float gridScale;
+
+vec4 main(float2 fragCoord) {
+    float gridUnit = 1.0 / gridScale;
+  	float m1 = step(mod(fragCoord.x + gridUnit, 10.0), gridUnit);
+    float m2 = step(mod(fragCoord.y + gridUnit, 10.0), gridUnit);
+    float fin = max(m1, m2);
+
+    vec4 pointColorUnmultiplied = vec4(gridColor.rgb, 1.0);
+
+  	return pointColorUnmultiplied * gridColor.a * fin;
+})V";
+
+const char* ruledShaderCode = R"V(
+uniform vec4 gridColor;
+uniform float gridScale;
+
+vec4 main(float2 fragCoord) {
+    float gridUnit = 1.0 / gridScale;
+    float fin = step(mod(fragCoord.y + gridUnit, 10.0), gridUnit);
+
+    vec4 pointColorUnmultiplied = vec4(gridColor.rgb, 1.0);
+
+  	return pointColorUnmultiplied * gridColor.a * fin;
+})V";
+
+sk_sp<SkRuntimeEffect> WorldGrid::compile_effect_shader_init(const char* shaderName, const char* shaderCode) {
+    auto [effect, err] = SkRuntimeEffect::MakeForShader(SkString(shaderCode));
+    if(!err.isEmpty()) {
+        std::cout << "[GridManager::compile_effect_shader_init] " << shaderName << " shader construction error\n";
+        std::cout << err.c_str() << std::endl;
+        throw std::runtime_error("Shader Compile Failure");
+    }
+    return effect;
+}
+
+sk_sp<SkShader> WorldGrid::get_shader(GridType gType, const SkColor4f& gridColor, float gridScale) {
+    sk_sp<SkRuntimeEffect> runtimeEffect;
+    switch(gType) {
+        case GridType::CIRCLE_POINTS:
+            runtimeEffect = circlePointEffect;
+            break;
+        case GridType::SQUARE_POINTS:
+            runtimeEffect = squarePointEffect;
+            break;
+        case GridType::SQUARE_LINES:
+            runtimeEffect = squareLinesEffect;
+            break;
+        case GridType::RULED:
+            runtimeEffect = ruledEffect;
+            break;
+    }
+    SkRuntimeShaderBuilder builder(runtimeEffect);
+    builder.uniform("gridColor") = gridColor;
+    builder.uniform("gridScale") = gridScale;
+    sk_sp<SkShader> s = builder.makeShader();
+    return s;
+}
+
+void WorldGrid::draw(GridManager& gMan, SkCanvas* canvas, const DrawData& drawData) {
+    if(!circlePointEffect) {
+        circlePointEffect = compile_effect_shader_init("Circle Point", circlePointShaderCode);
+        squarePointEffect = compile_effect_shader_init("Square Point", squarePointShaderCode);
+        squareLinesEffect = compile_effect_shader_init("Square Lines", squareLinesShaderCode);
+        ruledEffect = compile_effect_shader_init("Ruled", ruledShaderCode);
+    }
+
+    float alteredZoom = static_cast<float>(((size / WorldScalar(GRID_CACHE_SIZE_INT)) / drawData.cam.c.inverseScale));
+    if(alteredZoom > 0.5f) {
+        Vector2f fracCamPos;
+
+        fracCamPos.x() = static_cast<float>((drawData.cam.c.pos.x() % size) / drawData.cam.c.inverseScale);
+        fracCamPos.y() = static_cast<float>((drawData.cam.c.pos.y() % size) / drawData.cam.c.inverseScale);
+
+        SkPaint linePaint;
+        SkColor4f pointColor = gMan.world.canvasTheme.toolFrontColor;
+        pointColor.fA = std::clamp(alteredZoom / 20.0f, 0.0f, 0.4f);
+        linePaint.setShader(get_shader(gridType, pointColor, alteredZoom));
+
+        canvas->save();
+
+        canvas->rotate(-drawData.cam.c.rotation * 180.0 / std::numbers::pi);
+        canvas->translate(-fracCamPos.x(), -fracCamPos.y());
+        canvas->scale(alteredZoom, alteredZoom);
+
+        canvas->drawPaint(linePaint);
+
+        canvas->restore();
+    }
+}