From 1ebd4a748caa377375b2eaba30c8276347f8ea77 Mon Sep 17 00:00:00 2001
From: Dany LE <xsang.le@gmail.com>
Date: Tue, 15 Feb 2022 22:01:26 +0100
Subject: [PATCH] correct mouse position inside shader coodinate system

---
 Diya/DiyaBoot.class.st           |  4 ++--
 Diya/GLSimpleShader.class.st     |  6 ++++--
 Diya/OpenGLSL.class.st           |  2 +-
 Diya/SimpleDiyaRenderer.class.st | 15 ++++++++++-----
 4 files changed, 17 insertions(+), 10 deletions(-)

diff --git a/Diya/DiyaBoot.class.st b/Diya/DiyaBoot.class.st
index 2973141..ffd85d2 100644
--- a/Diya/DiyaBoot.class.st
+++ b/Diya/DiyaBoot.class.st
@@ -80,11 +80,11 @@ DiyaBoot >> initialize [
 DiyaBoot >> processEvent: event [
 	|mappedEvt|
 	mappedEvt := event mapped.
-	mappedEvt type = SDL_KEYDOWN ifTrue: [ Transcript show: 'keydown...'. ^running := false. ].
+	mappedEvt type = SDL_KEYDOWN ifTrue: [ Transcript show: 'keydown...';cr. ^running := false. ].
 	mappedEvt type = SDL_QUIT ifTrue:[ ^running:= false ].
 	mappedEvt type = SDL_FINGERDOWN ifTrue:[^self setCursorPosition: mappedEvt ].
 	mappedEvt type = SDL_FINGERMOTION ifTrue:[^self setCursorPosition: mappedEvt ].
-	mappedEvt type = SDL_MOUSEMOTION ifTrue:[DiyaRendererContext uniqueInstance mouse: mappedEvt].
+	mappedEvt type = SDL_MOUSEMOTION ifTrue:[DiyaRendererContext uniqueInstance mouse: (mappedEvt x) @ (mappedEvt y)].
 ]
 
 { #category : #events }
diff --git a/Diya/GLSimpleShader.class.st b/Diya/GLSimpleShader.class.st
index 3d4e2e0..c712ed5 100644
--- a/Diya/GLSimpleShader.class.st
+++ b/Diya/GLSimpleShader.class.st
@@ -15,8 +15,10 @@ uniform vec2 u_mouse;
 uniform float u_time;
 void main()
 {
-    vec2 mouse = vec2(u_mouse)/vec2(u_resolution);
-    gl_FragColor = vec4(mouse.x, mouse.y, abs(sin(u_time)), 1.0);
+	vec2 mouse = u_mouse / u_resolution;
+   vec2 px = (gl_FragCoord.xy/u_resolution);
+
+    gl_FragColor = vec4(px/mouse, abs(sin(u_time)), 1.0);
 }
 '
 ]
diff --git a/Diya/OpenGLSL.class.st b/Diya/OpenGLSL.class.st
index 83bb4f5..b9fdf84 100644
--- a/Diya/OpenGLSL.class.st
+++ b/Diya/OpenGLSL.class.st
@@ -214,7 +214,7 @@ OpenGLSL >> locateUniforms [
 OpenGLSL >> setUniform: uname value: values [
 	|uniform|
 	uniform := uniforms at: uname asSymbol ifAbsent:[
-		^self error: 'Uniform', uname, 'is not defined in this program'].
+		^self error: 'Uniform ', uname, ' is not defined in this program'].
 	uniform value: values
 ]
 
diff --git a/Diya/SimpleDiyaRenderer.class.st b/Diya/SimpleDiyaRenderer.class.st
index 89bf219..e6dbebf 100644
--- a/Diya/SimpleDiyaRenderer.class.st
+++ b/Diya/SimpleDiyaRenderer.class.st
@@ -22,7 +22,7 @@ SimpleDiyaRenderer >> initialize [
 	super initialize.
 	vertexBuffer := OpenGLVertexBuffer new.
 	arrayBuffer := OpenGLVertexArray new.
-	bufferData := FFIExternalArray externalNewType: GLfloat size: 9.
+	bufferData := FFIExternalArray externalNewType: GLfloat size: 12.
 	bufferData autoRelease.
 	shader := GLSimpleShader uniqueInstance.
 	
@@ -36,13 +36,15 @@ SimpleDiyaRenderer >> render [
 	shader setUniform: #u_time value: DiyaClock uniqueInstance elapsedTime asFloat.
 	shader setUniform: #u_resolution value: { context resolution x. context resolution y }.
 	context mouse ifNotNil: [
-		shader setUniform: #u_mouse value: { context mouse x. context mouse y }.
+		"in shader, window origin is bottom left conor of the window
+		the mouse position should be transformed to this coodinate"
+		shader setUniform: #u_mouse value: { context mouse x. context resolution y - context mouse y }.
 	].
  
 	arrayBuffer enableAttribute: 0.
 	vertexBuffer bind: GL_ARRAY_BUFFER.
 	OpenGLVertexArray  vertexAttributePointerIndex: 0 size:3  type: GL_FLOAT normalized: GL_FALSE stride: 0 pointer: nil .
-	OpenGL drawArrays: GL_TRIANGLES first:0  count: 3.
+	OpenGL drawArrays: GL_QUADS first:0  count: 4.
 	arrayBuffer disableAttribute: 0.
 ]
 
@@ -55,9 +57,12 @@ bufferData
 		at: 4 put: 1.0;
 		at: 5 put: -1.0;
 		at: 6 put: 0;
-		at: 7 put: 0;
+		at: 7 put: 1.0;
 		at: 8 put: 1.0;
-		at: 9 put: 0.
+		at: 9 put: 0;
+		at: 10 put: -1.0;
+		at: 11 put: 1.0;
+		at: 12 put: 0.
 	arrayBuffer 	bind.
 	vertexBuffer bind: GL_ARRAY_BUFFER.
 	vertexBuffer data: GL_ARRAY_BUFFER data:bufferData  usage: GL_STATIC_DRAW.