1 files changed, 64 insertions, 0 deletions
diff --git a/themes/src/summer/sky_model.cpp b/themes/src/summer/sky_model.cpp
new file mode 100644
index 0000000..d700f34
--- /dev/null
+++ b/themes/src/summer/sky_model.cpp
@@ -0,0 +1,64 @@
+#include "sky_model.h"
+#include "../webgl_context.h"
+#include "../mathlib.h"
+#include "../shaders/sky_vert.h"
+#include "../shaders/sky_frag.h"
+
+SkyModel::SkyModel() {}
+
+SkyModel::~SkyModel() { unload(); }
+
+void SkyModel::load(WebglContext* inContext) {
+    context = inContext;
+    shader = loadShader(shader_sky_vert, shader_sky_frag);
+    useShader(shader);
+
+    attributes.position = getShaderAttribute(shader, "position");
+    uniforms.time       = getShaderUniform(shader, "time");
+    uniforms.horizon    = getShaderUniform(shader, "horizon");
+
+    // Full-screen quad in clip space (two triangles).
+    Vector2 verts[6] = {
+        Vector2(-1.f, -1.f), Vector2(1.f, -1.f), Vector2(-1.f, 1.f),
+        Vector2(-1.f,  1.f), Vector2(1.f, -1.f), Vector2( 1.f, 1.f)
+    };
+
+    glGenVertexArrays(1, &vao);
+    glBindVertexArray(vao);
+
+    glGenBuffers(1, &vbo);
+    glBindBuffer(GL_ARRAY_BUFFER, vbo);
+    glBufferData(GL_ARRAY_BUFFER, sizeof(verts), verts, GL_STATIC_DRAW);
+
+    glEnableVertexAttribArray(attributes.position);
+    glVertexAttribPointer(attributes.position, 2, GL_FLOAT, GL_FALSE, sizeof(Vector2), (GLvoid*)0);
+
+    glBindVertexArray(0);
+}
+
+void SkyModel::update(f32 dtSeconds) {
+    elapsedTime += dtSeconds;
+}
+
+void SkyModel::render() {
+    useShader(shader);
+
+    // Background: paint every pixel first, without touching the depth buffer so
+    // it can neither reject nor be rejected by the sun/water drawn afterward.
+    glDepthMask(GL_FALSE);
+    glDisable(GL_DEPTH_TEST);
+    glDisable(GL_BLEND);
+
+    setShaderFloat(uniforms.time, elapsedTime);
+    setShaderFloat(uniforms.horizon, horizon);
+
+    glBindVertexArray(vao);
+    glDrawArrays(GL_TRIANGLES, 0, 6);
+    glBindVertexArray(0);
+}
+
+void SkyModel::unload() {
+    if (vao) { glDeleteVertexArrays(1, &vao); vao = 0; }
+    if (vbo) { glDeleteBuffers(1, &vbo); vbo = 0; }
+    if (shader) { glDeleteProgram(shader); shader = 0; }
+}