contributed simple shader example (#973)

Contributed simple shader example

examples/Makefile

@@ -437,6 +437,8 @@ EXAMPLES = \
     shaders/shaders_julia_set \
     shaders/shaders_eratosthenes \
     shaders/shaders_basic_lighting \
+    shaders/shaders_fog \
+    shaders/shaders_simple \
     audio/audio_module_playing \
     audio/audio_music_stream \
     audio/audio_raw_stream \

examples/shaders/resources/shaders/glsl330/mask.fs

@@ -0,0 +1,21 @@
+#version 330
+
+// Input vertex attributes (from vertex shader)
+in vec2 fragTexCoord;
+
+// Input uniform values
+uniform sampler2D texture0;
+uniform sampler2D mask;
+uniform int frame;
+
+// Output fragment color
+out vec4 finalColor;
+
+void main()
+{
+    vec4 maskColour = texture(mask, fragTexCoord+vec2(sin(-frame/150.0)/10.0,cos(-frame/170.0)/10.0));
+    if (maskColour.r < 0.25) discard;
+    vec4 texelColor = texture(texture0, fragTexCoord+vec2(sin(frame/90.0)/8.0,cos(frame/60.0)/8.0));
+
+    finalColor = texelColor * maskColour;
+}

examples/shaders/resources/shaders/glsl330/mask.vs

@@ -0,0 +1,21 @@
+#version 330
+
+// Input vertex attributes
+in vec3 vertexPosition;
+in vec2 vertexTexCoord;
+
+// Input uniform values
+uniform mat4 mvp;
+uniform mat4 matModel;
+
+// Output vertex attributes (to fragment shader)
+out vec2 fragTexCoord;
+
+void main()
+{
+    // Send vertex attributes to fragment shader
+    fragTexCoord = vertexTexCoord;
+
+    // Calculate final vertex position
+    gl_Position = mvp*vec4(vertexPosition, 1.0);
+}

examples/shaders/shaders_simple.c

@@ -0,0 +1,153 @@
+/*******************************************************************************************
+*
+*   raylib [shaders] example - demonstrates how you can use your own simple shaders in raylib
+*
+*   This example has been created using raylib 2.5 (www.raylib.com)
+*   raylib is licensed under an unmodified zlib/libpng license (View raylib.h for details)
+*
+*   Example contributed by Chris Camacho (@codifies) and reviewed by Ramon Santamaria (@raysan5)
+*
+*   Copyright (c) 2019 Chris Camacho (@codifies) and Ramon Santamaria (@raysan5)
+*
+********************************************************************************************
+*
+* after a model is loaded it has a default material, this material can be modified in place
+* rather than creating one from scratch...
+* While all of the MAPs have particular names, they can be used for any purpose
+* Three of the MAP are applied as cubic maps (see below)
+*
+********************************************************************************************/
+
+
+#include <stddef.h>
+
+#include "raylib.h"
+#include "raymath.h"
+
+
+#define screenWidth 1280
+#define screenHeight 720
+
+
+int main(void)
+{
+    // Initialization
+    //--------------------------------------------------------------------------------------
+    InitWindow(screenWidth, screenHeight, "raylib - simple shader");
+
+    // Define the camera to look into our 3d world
+    Camera camera = { 0 };
+    camera.position = (Vector3){ 0.0f, 1.0f, 2.0f };
+    camera.target = (Vector3){ 0.0f, 0.0f, 0.0f };
+    camera.up = (Vector3){ 0.0f, 1.0f, 0.0f };
+    camera.fovy = 45.0f;
+    camera.type = CAMERA_PERSPECTIVE;
+
+    // three models to show the shader on
+    Mesh torus = GenMeshTorus(.3, 1, 16, 32);
+    Model model1 = LoadModelFromMesh(torus);
+
+    Mesh cube = GenMeshCube(.8,.8,.8);
+    Model model2 = LoadModelFromMesh(cube);
+
+    // this one un shaded just so we can see the gaps in the other two
+    Mesh sphere = GenMeshSphere(1, 16, 16);
+    Model model3 = LoadModelFromMesh(sphere);
+
+    // load the shader
+    Shader shader = LoadShader("resources/shaders/glsl330/mask.vs",
+                                "resources/shaders/glsl330/mask.fs");
+
+    // apply the diffuse texture (colour map)
+    Texture tex = LoadTexture("resources/plasma.png");
+    model1.materials[0].maps[MAP_DIFFUSE].texture = tex;
+    model2.materials[0].maps[MAP_DIFFUSE].texture = tex;
+
+    // using MAP_EMISSION as a spare slot to use for 2nd texture
+    // dont use MAP_IRRADIANCE, MAP_PREFILTER, or  MAP_CUBEMAP
+    // as they are bound as cube maps (which don't see to work at all on my machine!)
+    Texture maskTx = LoadTexture("resources/mask.png");
+    model1.materials[0].maps[MAP_EMISSION].texture = maskTx;
+    model2.materials[0].maps[MAP_EMISSION].texture = maskTx;
+    shader.locs[LOC_MAP_EMISSION] = GetShaderLocation(shader, "mask");
+
+    // frame is incremented each frame to animate the shader
+    int shaderFrame = GetShaderLocation(shader, "frame");
+
+    // apply the shader to the two models
+    model1.materials[0].shader = shader;
+    model2.materials[0].shader = shader;
+
+
+    // frame counter
+    int frame = 0;
+
+    // model rotation
+    Vector3 ang = { 0 };
+
+    SetTargetFPS(60);               // Set  to run at 60 frames-per-second
+    //--------------------------------------------------------------------------------------
+
+
+
+    // Main game loop
+    while (!WindowShouldClose())    // Detect window close button or ESC key
+    {
+        // Update
+        //----------------------------------------------------------------------------------
+
+        frame ++;
+        ang.x += 0.01;
+        ang.y += 0.005;
+        ang.z -= 0.0025;
+
+        // animate the shader
+        SetShaderValue(shader, shaderFrame, &frame, UNIFORM_INT);
+
+        // rotate one of the models
+        model1.transform = MatrixRotateXYZ(ang);
+
+        UpdateCamera(&camera);
+
+        // Draw
+        //----------------------------------------------------------------------------------
+        BeginDrawing();
+
+            ClearBackground(DARKBLUE);
+
+            BeginMode3D(camera);
+
+                DrawModel(model1, (Vector3){0.5,0,0}, 1, WHITE);
+                DrawModelEx(model2, (Vector3){-.5,0,0}, (Vector3){1,1,0}, 50, (Vector3){1,1,1}, WHITE);
+                DrawModel(model3,(Vector3){0,0,-1.5}, 1, WHITE);
+                DrawGrid(10, 1.0f);        // Draw a grid
+
+            EndMode3D();
+
+            DrawFPS(10, 10);
+
+            int l = MeasureText(FormatText("Frame %i", frame), 20);
+            DrawRectangle(16, 698, l+8, 42, BLUE);
+            DrawText(FormatText("Frame %i", frame), 20, 700, 20, WHITE);
+
+        EndDrawing();
+        //----------------------------------------------------------------------------------
+    }
+
+    // De-Initialization
+    //--------------------------------------------------------------------------------------
+
+    UnloadModel(model1);
+    UnloadModel(model2);
+    UnloadModel(model3);
+    UnloadTexture(tex);
+    UnloadTexture(maskTx);
+    UnloadShader(shader);
+
+    CloseWindow();        // Close window and OpenGL context
+    //--------------------------------------------------------------------------------------
+
+    return 0;
+}
+
+