Switch Inochi2D to premultipled alpha

Inochi2D · Jan 23, 2022 · 7bb3920 · 7bb3920
1 parent fc08476
commit 7bb3920
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Showing 5 changed files with 42 additions and 7 deletions.
diff --git a/shaders/basic/basic.frag b/shaders/basic/basic.frag
@@ -12,5 +12,5 @@ uniform sampler2D fbo;
 uniform float opacity;
 
 void main() {
-    outColor = texture(fbo, texUVs) * vec4(1, 1, 1, opacity);
+    outColor = texture(fbo, texUVs) * opacity;
 }
diff --git a/source/inochi2d/core/dbg.d b/source/inochi2d/core/dbg.d
@@ -99,6 +99,8 @@ void inDbgSetBuffer(vec3[] points, ushort[] indices) {
 */
 void inDbgDrawPoints(vec4 color, mat4 transform = mat4.identity) {
     glEnable(GL_POINT_SMOOTH);
+    glBlendFuncSeparate(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_ONE, GL_ONE);
+
         glBindVertexArray(dbgVAO);
 
         dbgShader.use();
@@ -112,6 +114,7 @@ void inDbgDrawPoints(vec4 color, mat4 transform = mat4.identity) {
         glDrawElements(GL_POINTS, indiceCount, GL_UNSIGNED_SHORT, null);
         glDisableVertexAttribArray(0);
 
+    glBlendFuncSeparate(GL_ONE, GL_ONE_MINUS_SRC_ALPHA, GL_ONE, GL_ONE);
     glDisable(GL_POINT_SMOOTH);
 }
 
@@ -120,6 +123,8 @@ void inDbgDrawPoints(vec4 color, mat4 transform = mat4.identity) {
 */
 void inDbgDrawLines(vec4 color, mat4 transform = mat4.identity) {
     glEnable(GL_LINE_SMOOTH);
+    glBlendFuncSeparate(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_ONE, GL_ONE);
+
         glBindVertexArray(dbgVAO);
 
         dbgShader.use();
@@ -133,5 +138,6 @@ void inDbgDrawLines(vec4 color, mat4 transform = mat4.identity) {
         glDrawElements(GL_LINES, indiceCount, GL_UNSIGNED_SHORT, null);
         glDisableVertexAttribArray(0);
 
+    glBlendFuncSeparate(GL_ONE, GL_ONE_MINUS_SRC_ALPHA, GL_ONE, GL_ONE);
     glDisable(GL_LINE_SMOOTH);
 }
diff --git a/source/inochi2d/core/nodes/part/package.d b/source/inochi2d/core/nodes/part/package.d
@@ -484,7 +484,7 @@ void inDrawTextureAtPart(Texture texture, Part part) {
     partShader.use();
     partShader.setUniform(mvp, 
         inGetCamera().matrix * 
-        mat4.translation(part.transform.matrix() * vec3(1, 1, 1))
+        mat4.translation(vec3(part.transform.matrix() * vec4(1, 1, 1, 1)))
     );
     partShader.setUniform(gopacity, part.opacity);
 

diff --git a/source/inochi2d/core/package.d b/source/inochi2d/core/package.d
@@ -41,6 +41,8 @@ private {
     GLuint fColor;
     GLuint fStencil;
 
+    vec4 inClearColor;
+
 
     Shader[] blendingShaders;
 
@@ -70,6 +72,8 @@ package(inochi2d) {
         // Some defaults that should be changed by app writer
         inCamera = new Camera;
 
+        inClearColor = vec4(0, 0, 0, 0);
+
         // Shader for scene
         sceneShader = new Shader(import("scene.vert"), import("scene.frag"));
         sceneMVP = sceneShader.getUniformLocation("mvp");
@@ -95,7 +99,7 @@ package(inochi2d) {
 /**
     Begins rendering to the framebuffer
 */
-void inBeginScene() { 
+void inBeginScene() {
     glEnable(GL_BLEND);
     glDisable(GL_DEPTH_TEST);
 
@@ -104,13 +108,13 @@ void inBeginScene() {
 
     // Bind our framebuffer
     glBindFramebuffer(GL_DRAW_FRAMEBUFFER, fBuffer);
-    glClearColor(0, 0, 0, 0);
+    glClearColor(inClearColor.r, inClearColor.g, inClearColor.b, inClearColor.a);
     glClear(GL_COLOR_BUFFER_BIT);
 
     // Everything else is the actual texture used by the meshes at id 0
     glActiveTexture(GL_TEXTURE0);
 
-    glBlendFuncSeparate(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_ONE, GL_ONE);
+    glBlendFuncSeparate(GL_ONE, GL_ONE_MINUS_SRC_ALPHA, GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
 }
 
 /**
@@ -151,7 +155,7 @@ void inDrawScene(vec4 area) {
     glDisable(GL_CULL_FACE);
     glDisable(GL_DEPTH_TEST);
     glEnable(GL_BLEND);
-    glBlendFuncSeparate(GL_ONE, GL_ONE_MINUS_SRC_ALPHA, GL_ONE, GL_ONE);
+    glBlendFuncSeparate(GL_ONE, GL_ONE_MINUS_SRC_ALPHA, GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
 
     sceneShader.use();
     sceneShader.setUniform(sceneMVP, 
@@ -264,4 +268,11 @@ void inDumpViewport(ref ubyte[] dumpTo) {
 
         ri++;
     }
+}
+
+/**
+    Sets the background clear color
+*/
+void inSetClearColor(float r, float g, float b, float a) {
+    inClearColor = vec4(r, g, b, a);
 }
diff --git a/source/inochi2d/core/texture.d b/source/inochi2d/core/texture.d
@@ -202,7 +202,7 @@ public:
 
         // Set default filtering and wrapping
         this.setFiltering(Filtering.Linear);
-        this.setWrapping(Wrapping.Mirror);
+        this.setWrapping(Wrapping.Clamp);
     }
 
     /**
@@ -362,4 +362,22 @@ void inEndTextureLoading() {
     enforce(started, "Texture loading pass not started!");
     started = false;
     textureBindings.length = 0;
+}
+
+void inTexPremultiply(ref ubyte[] data) {
+    foreach(i; 0..data.length/4) {
+        data[((i*4)+0)] = cast(ubyte)((cast(int)data[((i*4)+0)] * cast(int)data[((i*4)+3)])/255);
+        data[((i*4)+1)] = cast(ubyte)((cast(int)data[((i*4)+1)] * cast(int)data[((i*4)+3)])/255);
+        data[((i*4)+2)] = cast(ubyte)((cast(int)data[((i*4)+2)] * cast(int)data[((i*4)+3)])/255);
+    }
+}
+
+void inTexUnPremuliply(ref ubyte[] data) {
+    foreach(i; 0..data.length/4) {
+        if (data[((i*4)+3)] == 0) continue;
+
+        data[((i*4)+0)] = cast(ubyte)(cast(int)data[((i*4)+0)] * 255 / cast(int)data[((i*4)+3)]);
+        data[((i*4)+1)] = cast(ubyte)(cast(int)data[((i*4)+1)] * 255 / cast(int)data[((i*4)+3)]);
+        data[((i*4)+2)] = cast(ubyte)(cast(int)data[((i*4)+2)] * 255 / cast(int)data[((i*4)+3)]);
+    }
 }