Added screen

src/display/screen.c

@@ -0,0 +1,112 @@
+/**
+ * Copyright (c) 2025 Dominic Masters
+ * 
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "screen.h"
+#include "assert/assert.h"
+#include "display/spritebatch/spritebatch.h"
+
+screen_t SCREEN;
+
+void screenInit(void) {
+  // Virtual backbuffer for dynamic resolution scaling
+  #if DISPLAY_SIZE_DYNAMIC == 1
+    frameBufferInit(&SCREEN.frameBuffer, DISPLAY_WIDTH, DISPLAY_HEIGHT);
+    cameraInit(&SCREEN.frameBufferCamera);
+    SCREEN.frameBufferCamera.projType = CAMERA_PROJECTION_TYPE_ORTHOGRAPHIC;
+    SCREEN.frameBufferCamera.viewType = CAMERA_VIEW_TYPE_MATRIX;
+    glm_lookat(
+      (vec3){0.0f, 0.0f, 1.0f},
+      (vec3){0.0f, 0.0f, 0.0f},
+      (vec3){0.0f, 1.0f, 0.0f},
+      SCREEN.frameBufferCamera.view
+    );
+    SCREEN.frameBufferCamera.nearClip = -1.0f;
+    SCREEN.frameBufferCamera.farClip = 1.0f;
+  #endif
+}
+
+void screenBind(void) {
+  #if DISPLAY_SIZE_DYNAMIC == 1
+    frameBufferBind(&SCREEN.frameBuffer);
+  #else
+    frameBufferBind(NULL);
+  #endif
+
+  frameBufferClear(
+    FRAMEBUFFER_CLEAR_COLOR | FRAMEBUFFER_CLEAR_DEPTH,
+    COLOR_CORNFLOWER_BLUE
+  );
+}
+
+void screenUnbindAndRender(void) {
+  assertTrue(SPRITEBATCH.spriteCount == 0, "Sprite batch not flushed");
+
+  // Render to real backbuffer
+  #if DISPLAY_SIZE_DYNAMIC == 1
+    frameBufferBind(NULL);
+    frameBufferClear(
+      FRAMEBUFFER_CLEAR_COLOR | FRAMEBUFFER_CLEAR_DEPTH,
+      COLOR_BLACK
+    );
+    
+
+    SCREEN.frameBufferCamera.orthographic.left = 0;
+    SCREEN.frameBufferCamera.orthographic.right = frameBufferGetWidth(
+      FRAMEBUFFER_BOUND
+    );
+    SCREEN.frameBufferCamera.orthographic.bottom = frameBufferGetHeight(
+      FRAMEBUFFER_BOUND
+    );
+    SCREEN.frameBufferCamera.orthographic.top = 0;
+    cameraPushMatrix(&SCREEN.frameBufferCamera);
+
+    vec2 backbuffer = {
+      (float_t)frameBufferGetWidth(FRAMEBUFFER_BOUND),
+      (float_t)frameBufferGetHeight(FRAMEBUFFER_BOUND)
+    };
+    vec2 virtual = {
+      (float_t)frameBufferGetWidth(&SCREEN.frameBuffer),
+      (float_t)frameBufferGetHeight(&SCREEN.frameBuffer)
+    };
+
+    // Compare aspect ratios.
+    vec4 viewport;
+    float_t backbufferAspect = backbuffer[0] / backbuffer[1];
+    float_t virtualAspect = virtual[0] / virtual[1];
+    if (backbufferAspect > virtualAspect) {
+      // Backbuffer is wider: pillarbox
+      float_t scale = backbuffer[1] / virtual[1];
+      float_t width = virtual[0] * scale;
+      viewport[0] = (backbuffer[0] - width) * 0.5f;
+      viewport[1] = 0;
+      viewport[2] = width;
+      viewport[3] = backbuffer[1];
+    } else {
+      // Backbuffer is taller: letterbox
+      float_t scale = backbuffer[0] / virtual[0];
+      float_t height = virtual[1] * scale;
+      viewport[0] = 0;
+      viewport[1] = (backbuffer[1] - height) * 0.5f;
+      viewport[2] = backbuffer[0];
+      viewport[3] = height;
+    }
+
+    spriteBatchPush(
+      &SCREEN.frameBuffer.texture,
+      viewport[0], viewport[1],
+      viewport[0] + viewport[2], viewport[1] + viewport[3],
+      COLOR_WHITE,
+      0.0f, 1.0f, 1.0f, 0.0f
+    );
+    spriteBatchFlush();
+    cameraPopMatrix();
+  #endif
+}
+
+void screenDispose(void) {
+  frameBufferDispose(&SCREEN.frameBuffer);
+}