GPU processing

main.c

@@ -41,7 +41,7 @@ void DrawLaserBeam(Vector2 start, Vector2 end, Color color, float thickness) {
     DrawLineEx(start, end, thickness, color);
 }
 
-void DrawInterferenceView(Michelson *mic, Rectangle rec) {
+void DrawInterferenceViewCPU(Michelson *mic, Rectangle rec) {
     DrawRectangleRec((Rectangle){rec.x - 4, rec.y - 30, rec.width + 8, rec.height + 34}, COLOR_PANEL);
     //DrawText("ECRAN", rec.x, rec.y - 30, 20, WHITE);
     DrawText("ECRAN", rec.x, rec.y - 26, 20, COLOR_TEXT_DIM);
@@ -93,6 +93,40 @@ void DrawInterferenceView(Michelson *mic, Rectangle rec) {
     DrawLine(cx, cy - 10, cx, cy + 10, Fade(WHITE, 0.5f));
 }
 
+void DrawInterferenceViewGPU(Michelson *mic, Rectangle rec, Shader shader) {
+    
+    DrawRectangleRec((Rectangle){rec.x - 4, rec.y - 30, rec.width + 8, rec.height + 34}, COLOR_PANEL);
+    DrawText("ECRAN", rec.x, rec.y - 26, 20, COLOR_TEXT_DIM);
+
+    // Shader glsl 
+    float centerX = rec.x + rec.width / 2.0f;
+    float centerY = rec.y + rec.height / 2.0f;
+    float center[2] = { centerX, centerY };
+    float scrHeight = (float)GetScreenHeight();
+
+    //
+    SetShaderValue(shader, GetShaderLocation(shader, "center"), center, SHADER_UNIFORM_VEC2);
+    SetShaderValue(shader, GetShaderLocation(shader, "screenHeight"), &scrHeight, SHADER_UNIFORM_FLOAT);
+    
+    SetShaderValue(shader, GetShaderLocation(shader, "d1"), &mic->d1, SHADER_UNIFORM_FLOAT);
+    SetShaderValue(shader, GetShaderLocation(shader, "d2"), &mic->d2, SHADER_UNIFORM_FLOAT);
+    SetShaderValue(shader, GetShaderLocation(shader, "lambda"), &mic->lambda, SHADER_UNIFORM_FLOAT);
+    SetShaderValue(shader, GetShaderLocation(shader, "angleM1"), &mic->angleM1, SHADER_UNIFORM_FLOAT);
+
+    // GPU
+    BeginShaderMode(shader);
+        DrawRectangleRec(rec, WHITE);
+    EndShaderMode();
+
+    DrawRectangleLinesEx(rec, 1, Fade(COLOR_ACCENT, 0.3f));
+    DrawRectangleLinesEx(rec, 2, COLOR_PANEL);
+    
+    int cx = rec.x + rec.width / 2;
+    int cy = rec.y + rec.height / 2;
+    DrawLine(cx - 10, cy, cx + 10, cy, Fade(WHITE, 0.5f));
+    DrawLine(cx, cy - 10, cx, cy + 10, Fade(WHITE, 0.5f));
+}
+
 void DrawMichelsonSchema (Michelson *mic) {
     Vector2 c = mic->center;
     Color laserColor = WavelengthToColor(mic->lambda);
@@ -231,6 +265,8 @@ int main () {
     InitWindow(1920, 1080, "Interferometre de Michelson");
     SetTargetFPS(144);
 
+    Shader shader = LoadShader(0, "michelson.fs");
+
     Michelson mic = {0};
     mic.center = (Vector2){ UI_WIDTH + (1920 - UI_WIDTH) / 2.0f - 100, 1080 / 2.0f };
     mic.d1 = 250.0f;
@@ -245,12 +281,12 @@ int main () {
         BeginDrawing();
             ClearBackground(COLOR_BG);
             // Grille fond
-            for(int i=UI_WIDTH; i<1920; i+=100) DrawLine(i, 0, i, 1080, Fade(WHITE, 0.05f));
+            for(int i = UI_WIDTH; i < 1920; i += 100) DrawLine(i, 0, i, 1080, Fade(WHITE, 0.05f));
-            for(int i=0; i<1080; i+=100) DrawLine(UI_WIDTH, i, 1920, i, Fade(WHITE, 0.05f));
+            for(int i = 0; i < 1080; i += 100) DrawLine(UI_WIDTH, i, 1920, i, Fade(WHITE, 0.05f));
 
             DrawMichelsonSchema(&mic);
             DrawControlPanel(&mic);
-            DrawInterferenceView(&mic, screenViewBounds);
+            DrawInterferenceViewGPU(&mic, screenViewBounds, shader);
         EndDrawing();
     }
     CloseWindow();

michelson.fs

@@ -0,0 +1,68 @@
+#version 330
+
+// Entrées (de Raylib)
+in vec2 fragTexCoord;
+in vec4 fragColor;
+
+out vec4 finalColor;
+
+uniform vec2 center;
+uniform float screenHeight;
+uniform vec2 resolution;
+uniform float d1;
+uniform float d2;
+uniform float lambda;
+uniform float angleM1;
+
+const float PI = 3.14159265359;
+
+vec3 WavelengthToRGB(float l) {
+    float r = 0.0; float g = 0.0; float b = 0.0;
+    if (l >= 380.0 && l < 440.0) { r = -(l - 440.0) / (440.0 - 380.0); b = 1.0; }
+    else if (l >= 440.0 && l < 490.0) { g = (l - 440.0) / (490.0 - 440.0); b = 1.0; }
+    else if (l >= 490.0 && l < 510.0) { g = 1.0; b = -(l - 510.0) / (510.0 - 490.0); }
+    else if (l >= 510.0 && l < 580.0) { r = (l - 510.0) / (580.0 - 510.0); g = 1.0; }
+    else if (l >= 580.0 && l < 645.0) { r = 1.0; g = -(l - 645.0) / (645.0 - 580.0); }
+    else if (l >= 645.0 && l <= 780.0) { r = 1.0; }
+
+    float factor = 1.0;
+    if (l >= 380.0 && l < 420.0) factor = 0.3 + 0.7 * (l - 380.0) / (420.0 - 380.0);
+    else if (l >= 380.0 && l <= 645.0) factor = 1.0;
+    else if (l > 700.0 && l <= 780.0) factor = 0.3 + 0.7 * (780.0 - l) / (780.0 - 700.0);
+
+    return vec3(r * factor, g * factor, b * factor);
+}
+
+void main() {
+    float pixelX = gl_FragCoord.x;
+    float pixelY = screenHeight - gl_FragCoord.y;
+
+    // Diff de marche du à l'axe (2 * e) + micro -> nano
+    float deltaLnm = 2.0 * (d1 - d2) * 1000.0;
+
+    float relX = (pixelX - center.x);
+    float relY = (pixelY - center.y);
+   
+    vec3 baseColorVec = WavelengthToRGB(lambda);
+
+    // r^2
+    float radiusSq = relX * relX + relY * relY;
+
+    // Diff de marche lamme d'air 2 * e cos(i) mais petits angles => cos(i) ~ 1 - i^2/2 mais i ~ r/f et r^2 = x^2 + y^2
+    float ringFactor = radiusSq * 0.065;
+
+    // Diff de marche du au coin d'air
+    float wDelta = relX * angleM1 * 200.0;
+
+    float currDelta = deltaLnm - ringFactor + wDelta;
+
+    // Formule de Fresnel : I = I_0 * cos^2(phi)
+    float K = PI / lambda;
+    float phase = currDelta * K;
+    float intensity = cos(phase);
+    intensity = intensity * intensity;
+
+    vec3 finalVec = baseColorVec * intensity;
+
+    finalColor = vec4(finalVec, 1.0);
+}