added skybox example

Author: Pebaz

examples/models/models_skybox.py

@@ -0,0 +1,67 @@
+from raylib.dynamic import raylib as rl, ffi
+from raylib.colors import *
+
+screenWidth = 1260
+screenHeight = 768
+
+rl.InitWindow(screenWidth, screenHeight, b'Skymap Demo')
+
+camera = ffi.new('struct Camera3D *', [[1, 1, 1], [4, 1, 4], [0, 1, 0], 70, 0])
+
+cube = rl.GenMeshCube(100, 100, 100)
+skybox = rl.LoadModelFromMesh(cube)
+
+skybox.materials[0].shader = rl.LoadShader(
+	b'res/shader/skybox.vs.glsl',
+	b'res/shader/skybox.fs.glsl'
+)
+
+rl.SetShaderValue(
+	skybox.materials[0].shader,
+	rl.GetShaderLocation(skybox.materials[0].shader, b"environmentMap"),
+	ffi.new('int[]', [rl.MAP_CUBEMAP]),
+	rl.UNIFORM_INT
+)
+
+shdrCubemap = rl.LoadShader(
+	b'res/shader/cubemap.vs.glsl',
+	b'res/shader/cubemap.fs.glsl'
+)
+
+rl.SetShaderValue(
+	shdrCubemap,
+	rl.GetShaderLocation(shdrCubemap, b'equirectangularMap'),
+	ffi.new('int[]', [0]),
+	rl.UNIFORM_INT
+)
+
+texHDR = rl.LoadTexture(b'res/img/skymap.hdr')
+
+skybox.materials[0].maps[rl.MAP_CUBEMAP].texture = rl.GenTextureCubemap(shdrCubemap, texHDR, 512);
+
+rl.UnloadTexture(texHDR)
+rl.UnloadShader(shdrCubemap)
+
+rl.SetCameraMode(camera[0], rl.CAMERA_FIRST_PERSON)
+
+rl.SetTargetFPS(60)
+
+while not rl.WindowShouldClose():
+	rl.UpdateCamera(camera)
+	rl.BeginDrawing()
+	rl.ClearBackground(RAYWHITE)
+	rl.BeginMode3D(camera[0])
+	rl.DrawModel(skybox, [0, 0, 0], 1.0, WHITE)
+	rl.DrawGrid(10, 1.0)
+	for x in range(10):
+		for y in range(10):
+			rl.DrawCube([x * 2, 0, y * 2], 1, 1, 1, MAROON)
+			rl.DrawCubeWires([x * 2, 0, y * 2], 1, 1, 1, RED)
+	rl.EndMode3D()
+	rl.DrawFPS(10, 10)
+	rl.EndDrawing()
+
+rl.CloseWindow()
+rl.UnloadShader(skybox.materials[0].shader)
+rl.UnloadTexture(skybox.materials[0].maps[rl.MAP_CUBEMAP].texture)
+rl.UnloadModel(skybox)

examples/res/img/skymap.hdr

@@ -0,0 +1,38 @@
+/*******************************************************************************************
+*
+*   rPBR [shader] - Equirectangular to cubemap fragment shader
+*
+*   Copyright (c) 2017 Victor Fisac
+*
+**********************************************************************************************/
+
+#version 330
+
+// Input vertex attributes (from vertex shader)
+in vec3 fragPosition;
+
+// Input uniform values
+uniform sampler2D equirectangularMap;
+
+// Output fragment color
+out vec4 finalColor;
+
+vec2 SampleSphericalMap(vec3 v)
+{
+    vec2 uv = vec2(atan(v.z, v.x), asin(v.y));
+    uv *= vec2(0.1591, 0.3183);
+    uv += 0.5;
+    return uv;
+}
+
+void main()
+{
+    // Normalize local position 
+    vec2 uv = SampleSphericalMap(normalize(fragPosition));
+
+    // Fetch color from texture map
+    vec3 color = texture(equirectangularMap, uv).rgb;
+
+    // Calculate final fragment color
+    finalColor = vec4(color, 1.0);
+}

examples/res/shader/cubemap.fs.glsl

@@ -0,0 +1,28 @@
+/*******************************************************************************************
+*
+*   rPBR [shader] - Equirectangular to cubemap vertex shader
+*
+*   Copyright (c) 2017 Victor Fisac
+*
+**********************************************************************************************/
+
+#version 330
+
+// Input vertex attributes
+in vec3 vertexPosition;
+
+// Input uniform values
+uniform mat4 projection;
+uniform mat4 view;
+
+// Output vertex attributes (to fragment shader)
+out vec3 fragPosition;
+
+void main()
+{
+    // Calculate fragment position based on model transformations
+    fragPosition = vertexPosition;
+
+    // Calculate final vertex position
+    gl_Position = projection*view*vec4(vertexPosition, 1.0);
+}

examples/res/shader/cubemap.vs.glsl

@@ -0,0 +1,31 @@
+/*******************************************************************************************
+*
+*   rPBR [shader] - Background skybox fragment shader
+*
+*   Copyright (c) 2017 Victor Fisac
+*
+**********************************************************************************************/
+
+#version 330
+
+// Input vertex attributes (from vertex shader)
+in vec3 fragPosition;
+
+// Input uniform values
+uniform samplerCube environmentMap;
+
+// Output fragment color
+out vec4 finalColor;
+
+void main()
+{
+    // Fetch color from texture map
+    vec3 color = texture(environmentMap, fragPosition).rgb;
+
+    // Apply gamma correction
+    color = color/(color + vec3(1.0));
+    color = pow(color, vec3(1.0/2.2));
+
+    // Calculate final fragment color
+    finalColor = vec4(color, 1.0);
+}

examples/res/shader/skybox.fs.glsl

@@ -0,0 +1,32 @@
+/*******************************************************************************************
+*
+*   rPBR [shader] - Background skybox vertex shader
+*
+*   Copyright (c) 2017 Victor Fisac
+*
+**********************************************************************************************/
+
+#version 330
+
+// Input vertex attributes
+in vec3 vertexPosition;
+
+// Input uniform values
+uniform mat4 projection;
+uniform mat4 view;
+
+// Output vertex attributes (to fragment shader)
+out vec3 fragPosition;
+
+void main()
+{
+    // Calculate fragment position based on model transformations
+    fragPosition = vertexPosition;
+
+    // Remove translation from the view matrix
+    mat4 rotView = mat4(mat3(view));
+    vec4 clipPos = projection*rotView*vec4(vertexPosition, 1.0);
+
+    // Calculate final vertex position
+    gl_Position = clipPos.xyzw;
+}