Lightmap example. (#3043)

7 files changed, 218 insertions, 0 deletions

diff --git a/examples/shaders/resources/LICENSE.md b/examples/shaders/resources/LICENSE.md
index 96458eca..7210e34b 100644
--- a/examples/shaders/resources/LICENSE.md
+++ b/examples/shaders/resources/LICENSE.md
@@ -9,3 +9,5 @@
 | raysan.png         | [@raysan5](https://github.com/raysan5)      | [CC0](https://creativecommons.org/publicdomain/zero/1.0/)   | - |
 | space.png          | ❔             | ❔       | - |
 | texel_checker.png  | [@raysan5](https://github.com/raysan5)      | [CC0](https://creativecommons.org/publicdomain/zero/1.0/)   | Made with [UV Checker Map Maker](http://uvchecker.byvalle.com/) |
+| cubicmap.png       | [@raysan5](https://github.com/raysan5)    | [CC0](https://creativecommons.org/publicdomain/zero/1.0/)     | - |
+| spark_flame.png      | [@raysan5](https://github.com/raysan5)    | [CC0](https://creativecommons.org/publicdomain/zero/1.0/)     | Made with [EffectTextureMaker](https://mebiusbox.github.io/contents/EffectTextureMaker/) |
\ No newline at end of file
diff --git a/examples/shaders/resources/cubicmap_atlas.png b/examples/shaders/resources/cubicmap_atlas.png
new file mode 100644
index 00000000..9fc404a7
--- /dev/null
+++ b/examples/shaders/resources/cubicmap_atlas.png
diff --git a/examples/shaders/resources/shaders/glsl330/lightmap.fs b/examples/shaders/resources/shaders/glsl330/lightmap.fs
new file mode 100644
index 00000000..95558610
--- /dev/null
+++ b/examples/shaders/resources/shaders/glsl330/lightmap.fs
@@ -0,0 +1,20 @@
+#version 330
+// Input vertex attributes (from vertex shader)
+in vec2 fragTexCoord;
+in vec2 fragTexCoord2;
+in vec3 fragPosition;
+in vec4 fragColor;
+
+// Input uniform values
+uniform sampler2D texture0;
+uniform sampler2D texture1;
+
+// Output fragment color
+out vec4 finalColor;
+
+void main() {
+	// Texel color fetching from texture sampler
+    vec4 texelColor = texture( texture0, fragTexCoord );
+    vec4 texelColor2 = texture( texture1, fragTexCoord2 );
+	finalColor = texelColor * texelColor2;
+}
diff --git a/examples/shaders/resources/shaders/glsl330/lightmap.vs b/examples/shaders/resources/shaders/glsl330/lightmap.vs
new file mode 100644
index 00000000..00278eaa
--- /dev/null
+++ b/examples/shaders/resources/shaders/glsl330/lightmap.vs
@@ -0,0 +1,27 @@
+#version 330
+// Input vertex attributes
+in vec3 vertexPosition;
+in vec2 vertexTexCoord;
+in vec2 vertexTexCoord2;
+in vec4 vertexColor;
+
+// Input uniform values
+uniform mat4 mvp;
+uniform mat4 matModel;
+
+// Output vertex attributes (to fragment shader)
+out vec3 fragPosition;
+out vec2 fragTexCoord;
+out vec2 fragTexCoord2;
+out vec4 fragColor;
+
+void main() {
+    // Send vertex attributes to fragment shader
+    fragPosition = vec3( matModel * vec4( vertexPosition, 1.0 ) );
+    fragTexCoord = vertexTexCoord;
+    fragTexCoord2 = vertexTexCoord2;
+    fragColor = vertexColor;
+
+    // Calculate final vertex position
+    gl_Position = mvp * vec4( vertexPosition, 1.0 );
+}
diff --git a/examples/shaders/resources/spark_flame.png b/examples/shaders/resources/spark_flame.png
new file mode 100644
index 00000000..72cea2e9
--- /dev/null
+++ b/examples/shaders/resources/spark_flame.png
diff --git a/examples/shaders/shaders_lightmap.c b/examples/shaders/shaders_lightmap.c
new file mode 100644
index 00000000..a37c9922
--- /dev/null
+++ b/examples/shaders/shaders_lightmap.c
@@ -0,0 +1,169 @@
+/*******************************************************************************************
+*
+*   raylib [shaders] example - lightmap
+*
+*   NOTE: This example requires raylib OpenGL 3.3 or ES2 versions for shaders support,
+*         OpenGL 1.1 does not support shaders, recompile raylib to OpenGL 3.3 version.
+*
+*   NOTE: Shaders used in this example are #version 330 (OpenGL 3.3).
+*
+*   Example contributed by Jussi Viitala (@nullstare) and reviewed by Ramon Santamaria (@raysan5)
+*
+*   Example licensed under an unmodified zlib/libpng license, which is an OSI-certified,
+*   BSD-like license that allows static linking with closed source software
+*
+*   Copyright (c) 2019-2023 Jussi Viitala (@nullstare) and Ramon Santamaria (@raysan5)
+*
+********************************************************************************************/
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "raylib.h"
+#include "raymath.h"
+#include "rlgl.h"
+
+#if defined(PLATFORM_DESKTOP)
+    #define GLSL_VERSION            330
+#else   // PLATFORM_RPI, PLATFORM_ANDROID, PLATFORM_WEB
+    #define GLSL_VERSION            100
+#endif
+
+#define MAP_SIZE 10
+
+//------------------------------------------------------------------------------------
+// Program main entry point
+//------------------------------------------------------------------------------------
+int main(void)
+{
+    // Initialization
+    //--------------------------------------------------------------------------------------
+    const int screenWidth = 800;
+    const int screenHeight = 450;
+
+    SetConfigFlags(FLAG_MSAA_4X_HINT);  // Enable Multi Sampling Anti Aliasing 4x (if available)
+    InitWindow(screenWidth, screenHeight, "raylib [shaders] example - lightmap");
+
+    // Define the camera to look into our 3d world
+    Camera camera = { 0 };
+    camera.position = (Vector3){ 2.0f, 4.0f, 6.0f };    // Camera position
+    camera.target = (Vector3){ 0.0f, 0.5f, 0.0f };      // Camera looking at point
+    camera.up = (Vector3){ 0.0f, 1.0f, 0.0f };          // Camera up vector (rotation towards target)
+    camera.fovy = 45.0f;                                // Camera field-of-view Y
+    camera.projection = CAMERA_PERSPECTIVE;             // Camera projection type
+
+	Mesh mesh = GenMeshPlane((float)MAP_SIZE, (float)MAP_SIZE, 1, 1);
+
+	// GenMeshPlane doesn't generate texcoords2 so we will upload them separately
+	mesh.texcoords2 = (float *)RL_MALLOC(mesh.vertexCount * 2 * sizeof(float));
+
+	// X						// Y
+	mesh.texcoords2[0] = 0.0f;	mesh.texcoords2[1] = 0.0f;
+	mesh.texcoords2[2] = 1.0f;	mesh.texcoords2[3] = 0.0f;
+	mesh.texcoords2[4] = 0.0f;	mesh.texcoords2[5] = 1.0f;
+	mesh.texcoords2[6] = 1.0f;	mesh.texcoords2[7] = 1.0f;
+
+	// Load a new texcoords2 attributes buffer
+	mesh.vboId[SHADER_LOC_VERTEX_TEXCOORD02] = rlLoadVertexBuffer(mesh.texcoords2, mesh.vertexCount*2*sizeof(float), false);
+	rlEnableVertexArray(mesh.vaoId);
+	// Index 5 is for texcoords2
+	rlSetVertexAttribute(5, 2, RL_FLOAT, 0, 0, 0);
+	rlEnableVertexAttribute(5);
+	rlDisableVertexArray();
+
+    // Load lightmap shader
+    Shader shader = LoadShader(TextFormat("resources/shaders/glsl%i/lightmap.vs", GLSL_VERSION),
+                               TextFormat("resources/shaders/glsl%i/lightmap.fs", GLSL_VERSION));
+
+	Texture texture = LoadTexture("resources/cubicmap_atlas.png");
+	Texture light = LoadTexture("resources/spark_flame.png");
+
+	GenTextureMipmaps(&texture);
+	SetTextureFilter(texture, TEXTURE_FILTER_TRILINEAR);
+
+	RenderTexture lightmap = LoadRenderTexture(MAP_SIZE, MAP_SIZE);
+
+	SetTextureFilter(lightmap.texture, TEXTURE_FILTER_TRILINEAR);
+
+ 	Material material = LoadMaterialDefault();
+    material.shader = shader;
+    material.maps[MATERIAL_MAP_ALBEDO].texture = texture;
+    material.maps[MATERIAL_MAP_METALNESS].texture = lightmap.texture;
+
+	// Drawing to lightmap
+	BeginTextureMode(lightmap);
+		ClearBackground(BLACK);
+
+		BeginBlendMode(BLEND_ADDITIVE);
+			DrawTexturePro(
+				light,
+				(Rectangle){ 0, 0, light.width, light.height },
+				(Rectangle){ 0, 0, 20, 20 },
+				(Vector2){ 10.0, 10.0 },
+				0.0,
+				RED
+			);
+			DrawTexturePro(
+				light,
+				(Rectangle){ 0, 0, light.width, light.height },
+				(Rectangle){ 8, 4, 20, 20 },
+				(Vector2){ 10.0, 10.0 },
+				0.0,
+				BLUE
+			);
+			DrawTexturePro(
+				light,
+				(Rectangle){ 0, 0, light.width, light.height },
+				(Rectangle){ 8, 8, 10, 10 },
+				(Vector2){ 5.0, 5.0 },
+				0.0,
+				GREEN
+			);
+		BeginBlendMode(BLEND_ALPHA);
+	EndTextureMode();
+
+    SetTargetFPS(60);                   // Set our game to run at 60 frames-per-second
+    //--------------------------------------------------------------------------------------
+
+    // Main game loop
+    while (!WindowShouldClose())        // Detect window close button or ESC key
+    {
+        // Update
+        //----------------------------------------------------------------------------------
+        UpdateCamera(&camera, CAMERA_ORBITAL);
+        //----------------------------------------------------------------------------------
+
+        // Draw
+        //----------------------------------------------------------------------------------
+        BeginDrawing();
+            ClearBackground(RAYWHITE);
+
+            BeginMode3D(camera);
+				DrawMesh(mesh, material, MatrixIdentity());
+            EndMode3D();
+
+            DrawFPS(10, 10);
+
+			DrawTexturePro(
+				lightmap.texture,
+				(Rectangle){ 0, 0, MAP_SIZE, MAP_SIZE },
+				(Rectangle){ 0, 36, MAP_SIZE * 4, MAP_SIZE * 4 },
+				(Vector2){ 0.0, 0.0 },
+				0.0,
+				WHITE
+			);
+        EndDrawing();
+        //----------------------------------------------------------------------------------
+    }
+
+    // De-Initialization
+    //--------------------------------------------------------------------------------------
+    UnloadMesh(mesh);     	// Unload the mesh
+    UnloadShader(shader);   // Unload shader
+
+    CloseWindow();          // Close window and OpenGL context
+    //--------------------------------------------------------------------------------------
+
+    return 0;
+}
+
diff --git a/examples/shaders/shaders_lightmap.png b/examples/shaders/shaders_lightmap.png
new file mode 100644
index 00000000..bdd8d3b9
--- /dev/null
+++ b/examples/shaders/shaders_lightmap.png