# HG changeset patch
# User Teemu Piippo <teemu@hecknology.net>
# Date 1646433855 -7200
# Node ID 65b75beed7e01b15449db8fead6a3d3eef93cf77
# Parent  13713fadbf14d17e05ded029e28eddc66f819cd0
render the grid with lines

diff -r 13713fadbf14 -r 65b75beed7e0 src/gl/gridprogram.cpp
--- a/src/gl/gridprogram.cpp	Fri Mar 04 23:41:58 2022 +0200
+++ b/src/gl/gridprogram.cpp	Sat Mar 05 00:44:15 2022 +0200
@@ -27,12 +27,11 @@
 uniform mat4 projection;
 uniform mat4 model;
 smooth out vec2 ex_uv;
-const mat4 stretch = mat4(vec4(1000, 0, 0, 0), vec4(0, 1000, 0, 0), vec4(0, 0, 1000, 0), vec4(0, 0, 0, 1));
 uniform mat4 grid;
 
 void main()
 {
-	gl_Position = projection * view * model * grid * stretch * vec4(in_position, 0.0, 1.0);
+	gl_Position = projection * view * model * grid * vec4(in_position, 0.0, 1.0);
 	ex_uv = in_position;
 }
 )";
@@ -43,26 +42,32 @@
 out vec4 color;
 smooth in vec2 ex_uv;
 uniform vec4 gridColor;
-const float pi = 3.14159265f;
 
 void main(void)
 {
-	float dx = fract(ex_uv.y / 0.001f);
-	float dy = fract(ex_uv.x / 0.001f);
-	/* compute distance to nearest unit line */
-	float d = min(min(min(dy, dx), 1 - dy), 1 - dx);
-	/* use an extreme sigmoid to bring out the grid shape */
-	d = pow(1.02 - d, 100);
+	float dx = fract(ex_uv.y);
+	float dy = fract(ex_uv.x);
 	/* fade the grid towards extreme co-ordinates */
-	d = (1.0f - 20 * max(abs(ex_uv.x), abs(ex_uv.y))) * d;
-	/* add dashes */
-	d *= (1 + pow(cos((ex_uv.y / 0.0001f) * pi), 10)) * 0.5f;
-	d *= (1 + pow(cos((ex_uv.x / 0.0001f) * pi), 10)) * 0.5f;
+	float d = (1.0f - 0.015 * max(abs(ex_uv.x), abs(ex_uv.y)));
 	color = vec4(gridColor.xyz, gridColor.w * d);
 }
 )";
 
-static const glm::vec2 data[] = {{-1, -1}, {-1, 1}, {1, 1}, {1, -1}};
+GridProgram::GridProgram(QObject *parent) :
+	AbstractBasicShaderProgram{parent}
+{
+	this->gridData.reserve(8004);
+	for (int i = -1000; i < 1000; i += 1)
+	{
+		this->gridData.push_back({i, -1000});
+		this->gridData.push_back({i, 1000});
+	}
+	for (int i = -1000; i < 1000; i += 1)
+	{
+		this->gridData.push_back({-1000, i});
+		this->gridData.push_back({1000, i});
+	}
+}
 
 void GridProgram::setGridMatrix(const glm::mat4& newGridMatrix)
 {
@@ -97,17 +102,17 @@
 
 const void* GridProgram::vertexData() const
 {
-	return ::data;
+	return this->gridData.data();
 }
 
 int GridProgram::vertexSize() const
 {
-	return sizeof data[0];
+	return sizeof this->gridData[0];
 }
 
 int GridProgram::vertexCount() const
 {
-	return glm::countof(data);
+	return this->gridData.size();
 }
 
 void GridProgram::setupVertexArrays()
@@ -119,7 +124,7 @@
 
 GLenum GridProgram::drawMode() const
 {
-	return GL_QUADS;
+	return GL_LINES;
 }
 
 QOpenGLBuffer::UsagePattern GridProgram::usagePattern() const
diff -r 13713fadbf14 -r 65b75beed7e0 src/gl/gridprogram.h
--- a/src/gl/gridprogram.h	Fri Mar 04 23:41:58 2022 +0200
+++ b/src/gl/gridprogram.h	Sat Mar 05 00:44:15 2022 +0200
@@ -24,7 +24,7 @@
 {
 	Q_OBJECT
 public:
-	using AbstractBasicShaderProgram::AbstractBasicShaderProgram;
+	GridProgram(QObject* parent = nullptr);
 	void setGridMatrix(const glm::mat4& newGridMatrix);
 	void setGridColor(const QColor& newGridColor);
 protected:
@@ -38,4 +38,5 @@
 	QOpenGLBuffer::UsagePattern usagePattern() const override;
 private:
 	glm::vec4 gridColor = {1.0f, 1.0f, 1.0f, 0.75f};
+	std::vector<glm::vec2> gridData;
 };