Fix a bug with glerminal_layer_scale that caused unintended behavior

CMakeLists.txt

@@ -31,7 +31,7 @@ target_include_directories(glerminal
 )
 
 target_link_libraries(glerminal
-	PUBLIC
+	PRIVATE
 		glfw
 )
 

examples/atlas.cpp

@@ -24,11 +24,11 @@ namespace
 			time = 0;
 		}
 
-		for (int i = 0; i < 40; i++)
+		for (int i = 0; i < GRID_WIDTH; i++)
 		{
-			for (int j = 0; j < 25; j++)
+			for (int j = 0; j < GRID_HEIGHT; j++)
 			{
-				for (int k = 0; k < 256; k++)
+				for (int k = 0; k < LAYER_COUNT; k++)
 				{
 					glerminal_set(i, j, k, rand() % 4);
 					glerminal_offset(i, j, k, (rand() * rand()) % 64 - 32, (rand() * rand()) % 64 - 32);

examples/basic.cpp

@@ -7,32 +7,28 @@ namespace
 	void init()
 	{
 		glerminal_load_sprites_file("resources/basic.png");
+
+		for (int i = 0; i < GRID_WIDTH; i++)
+		{
+			for (int j = 0; j < GRID_HEIGHT; j++)
+			{
+				glerminal_set(i, j, 0, 1);
+			}
+		}
 	}
 
 	void mainloop(float dt)
 	{
-		static float time = 1;
+		static float time = 0;
 
 		time += dt;
+		time = fmodf(time, 3.1415926f * 2);
 
-		if (time < 0.2f)
+		for (int i = 0; i < GRID_WIDTH; i++)
 		{
-			return;
+			for (int j = 0; j < GRID_HEIGHT; j++)
-		}
-		else
-		{
-			time = 0;
-		}
-
-		for (int i = 0; i < 40; i++)
-		{
-			for (int j = 0; j < 25; j++)
 			{
-				for (int k = 0; k < 256; k++)
+				glerminal_offset(i, j, 0, cosf(time - i / 3.1415f), sinf(time - j / 3.1415f));
-				{
-					glerminal_set(i, j, k, rand() % 3 == 0);
-					glerminal_offset(i, j, k, (rand() * rand()) % 64 - 32, (rand() * rand()) % 64 - 32);
-				}
 			}
 		}
 

examples/rogue.cpp

@@ -0,0 +1,87 @@
+#include <glerminal.h>
+
+#include <cmath>
+
+namespace
+{
+	enum : unsigned char
+	{
+		empty,
+		player,
+		floor,
+		wall
+	};
+
+	constexpr unsigned int WALL_LAYERS = LAYER_COUNT - 1;
+
+	void init()
+	{
+		glerminal_load_sprites_file("resources/rogue.png");
+
+		for (int i = 0; i < WALL_LAYERS; i++)
+		{
+			const unsigned char v = (i + 1) * (256 / WALL_LAYERS) - 1;
+			const unsigned int j = (0xFF << 24) | (v << 16) | (v << 8) | v;
+			glerminal_layer_color(i, j);
+
+			glerminal_layer_scale(i, (i / static_cast<float>(WALL_LAYERS)) + 1);
+		}
+
+		for (int i = 0; i < GRID_WIDTH; i++)
+		{
+			for (int j = 0; j < GRID_HEIGHT; j++)
+			{
+				for (int k = 0; k < WALL_LAYERS; k++)
+				{
+					if (i == 0 || j == 0 || i == GRID_WIDTH - 1 || j == GRID_HEIGHT - 1)
+					{
+						glerminal_set(i, j, k, floor);
+					}
+					else
+					{
+						glerminal_set(i, j, k, wall);
+					}
+				}
+			}
+		}
+	}
+
+	void mainloop(float dt)
+	{
+		static float time = 0;
+		time += dt;
+
+		const float cx = GRID_WIDTH / 2.0f * cosf(time / 2) + GRID_WIDTH / 2.0f;
+		const float cy = GRID_HEIGHT / 2.0f * sinf(time / 2) + GRID_HEIGHT / 2.0f;
+
+		for (int i = 0; i < GRID_WIDTH; i++)
+		{
+			for (int j = 0; j < GRID_HEIGHT; j++)
+			{
+				for (int k = 0; k < WALL_LAYERS; k++)
+				{
+					const float dx = (i - cx);
+					const float dy = (j - cy);
+					const float dist = sqrtf(dx * dx + dy * dy);
+					const float angle = atan2f(dy, dx);
+
+					const float ox = dist * k / WALL_LAYERS * cosf(angle);
+					const float oy = dist * k / WALL_LAYERS * sinf(angle);
+
+					glerminal_offset(i, j, k, ox * 2, oy * 2);
+				}
+
+				glerminal_set(i, j, WALL_LAYERS, empty);
+			}
+		}
+
+		glerminal_set(cx, cy, WALL_LAYERS, player);
+
+		glerminal_flush();
+	}
+}
+
+int main(int argc, char** argv)
+{
+	glerminal_run(init, mainloop);
+}

examples/towers.cpp

@@ -9,20 +9,20 @@ namespace
 	{
 		glerminal_load_sprites_file("resources/towers.png");
 
-		for (int i = 0; i < 256; i++)
+		for (int i = 0; i < LAYER_COUNT; i++)
 		{
-			constexpr unsigned char c = 0;
+			constexpr unsigned char c = 16;
-			const unsigned char v = (255 - c) * powf((i - 1) / 256.0f, 2.0f) + c;
+			const unsigned char v = (255 - c) * powf((256 / LAYER_COUNT * i - 1) / 256.0f, 2.0f) + c;
-			const unsigned int j = (0x7F << 24) | (v << 16) | (v << 8) | v;
+			const unsigned int j = (0xFF << 24) | (v << 16) | (v << 8) | v;
 			glerminal_layer_color(i, j);
-			glerminal_layer_scale(i, i / 256.0f + 1);
+			glerminal_layer_scale(i, i / static_cast<float>(LAYER_COUNT) + 1);
 		}
 
-		for (int i = 0; i < 40; i++)
+		for (int i = 0; i < GRID_WIDTH; i++)
 		{
-			for (int j = 0; j < 25; j++)
+			for (int j = 0; j < GRID_HEIGHT; j++)
 			{
-				const int c = rand() % 224 + 32;
+				const int c = rand() % (LAYER_COUNT * 3 / 4) + LAYER_COUNT / 4;
 				for (int k = 0; k < c; k++)
 				{
 					glerminal_set(i, j, k, 1);
@@ -37,18 +37,20 @@ namespace
 
 		time += dt;
 
-		const float cx = 20.0f * cosf(time / 3.1415f) + 20.0f;
+		const float cx = (GRID_WIDTH / 2.0f) * cosf(time / 3.1415f) + (GRID_WIDTH / 2.0f);
-		const float cy = 12.5f * sinf(time / 3.1415f) + 12.5f;
+		const float cy = (GRID_HEIGHT / 2.0f) * sinf(time / 3.1415f) + (GRID_HEIGHT / 2.0f);
 
-		for (int i = 0; i < 40; i++)
+		for (int i = 0; i < GRID_WIDTH; i++)
 		{
-			for (int j = 0; j < 25; j++)
+			for (int j = 0; j < GRID_WIDTH; j++)
 			{
-				for (int k = 0; k < 256; k++)
+				for (int k = 0; k < LAYER_COUNT; k++)
 				{
-					const float ox = 0.01f * k * (i - cx);
+					const float ox = (256.0f / LAYER_COUNT) * 0.0025f * k * (i - cx);
-					const float oy = 0.01f * k * (j - cy);
+					const float oy = (256.0f / LAYER_COUNT) * 0.0025f * k * (j - cy);
-					glerminal_offset(i, j, k, ox + (1 + 0.004f * k) * cosf(i + k * 6.2832f / 128.0f + 3.1415f * time), oy + (1 + 0.004f * k) * sinf(j + k * 6.2832f / 128.0f + 3.1415f * time));
+					const float sx = (1 + (256.0f / LAYER_COUNT) * 0.002f * k) * cosf(i + k * 6.2832f / 128.0f + 3.1415f * time / 1.5f);
+					const float sy = (1 + (256.0f / LAYER_COUNT) * 0.002f * k) * sinf(j + k * 6.2832f / 128.0f + 3.1415f * time / 1.5f);
+					glerminal_offset(i, j, k, ox + sx, oy + sy);
 				}
 			}
 		}

include/glerminal.h

@@ -6,6 +6,13 @@ extern "C"
 {
 #endif
 
+enum
+{
+	GRID_WIDTH = 40,
+	GRID_HEIGHT = 25,
+	LAYER_COUNT = 64
+};
+
 typedef void (*glerminal_init_cb)();
 typedef void (*glerminal_main_cb)(float dt);
 
@@ -60,8 +67,18 @@ void glerminal_layer_color(unsigned char layer, unsigned int color);
  */
 void glerminal_layer_scale(unsigned char layer, float scale);
 
+/**
+ * @brief Load sprites from a png file
+ * @param filename Name of the png file
+ */
 void glerminal_load_sprites_file(const char* filename);
 
+/**
+ * @brief Load sprites from memory
+ * @param width width of the atlas in sprites
+ * @param height height of the atlas in sprites
+ * @param buffer the in-memory atlas
+ */
 void glerminal_load_sprites_buffer(unsigned char width, unsigned char height, const unsigned int* buffer);
 
 #ifdef __cplusplus

source/glerminal-private.h

@@ -15,10 +15,9 @@ namespace glerminal
 	constexpr unsigned int SCREEN_WIDTH = 1280;
 	constexpr unsigned int SCREEN_HEIGHT = 800;
 	constexpr unsigned int CELL_SIZE = 8;
-	constexpr unsigned int CELL_SCALE = 4;
+	constexpr unsigned int LAYER_COUNT = ::LAYER_COUNT;
-	constexpr unsigned int LAYER_COUNT = 256;
+	constexpr unsigned int GRID_WIDTH = ::GRID_WIDTH;
-	constexpr unsigned int GRID_WIDTH = SCREEN_WIDTH / (CELL_SIZE * CELL_SCALE);
+	constexpr unsigned int GRID_HEIGHT = ::GRID_HEIGHT;
-	constexpr unsigned int GRID_HEIGHT = SCREEN_HEIGHT / (CELL_SIZE * CELL_SCALE);
 	constexpr unsigned int GRID_AREA = GRID_WIDTH * GRID_HEIGHT;
 
 	class glerminal

source/glerminal.cpp

@@ -6,6 +6,7 @@
 #define GRID_SIZE_UNIFORM_NAME "grid_size"
 #define SPRITES_UNIFORM_NAME "sprites"
 #define LAYERS_UNIFORM_NAME "layers"
+#define LAYER_COUNT_UNIFORM_NAME "layer_count"
 
 namespace
 {
@@ -30,6 +31,10 @@ namespace
 		"layout (location = 1) in vec2 offset;\n"
 		"layout (location = 2) in int sprite;\n"
 		"uniform vec4 " GRID_SIZE_UNIFORM_NAME ";\n"
+		"layout (std430, binding = 0) buffer LayerScales"
+		"{\n"
+		"	float scales[];\n"
+		"} lss;\n"
 		"out VS_OUT {\n"
 		"	flat vec2 offset;\n"
 		"	flat int sprite;\n"
@@ -38,12 +43,13 @@ namespace
 		"} vs_out;\n"
 		"void main()\n"
 		"{\n"
+		"	const int layer = int(floor(gl_InstanceID / " GRID_SIZE_UNIFORM_NAME ".y));\n"
 		"	vs_out.sprite = sprite;\n"
 		"	vs_out.offset = offset * " GRID_SIZE_UNIFORM_NAME ".zw;\n"
-		"	vs_out.layer = int(floor(gl_InstanceID / 1000));\n"
+		"	vs_out.layer = layer;\n"
 		"	vs_out.texcoord = vec2(position.x + 1, -position.y);\n"
-		"	vec2 cell_position = vec2(1 + (gl_InstanceID % 1000) - " GRID_SIZE_UNIFORM_NAME ".x * floor((gl_InstanceID % 1000) * " GRID_SIZE_UNIFORM_NAME ".z), -floor((gl_InstanceID % 1000) * " GRID_SIZE_UNIFORM_NAME ".z));\n"
+		"	vec2 cell_position = vec2(lss.scales[layer] + (gl_InstanceID % int(" GRID_SIZE_UNIFORM_NAME ".y)) - " GRID_SIZE_UNIFORM_NAME ".x * floor((gl_InstanceID % int(" GRID_SIZE_UNIFORM_NAME ".y)) * " GRID_SIZE_UNIFORM_NAME ".z), -floor((gl_InstanceID % int(" GRID_SIZE_UNIFORM_NAME ".y)) * " GRID_SIZE_UNIFORM_NAME ".z));\n"
-		"	vec2 temp = vec2((position + cell_position) * " GRID_SIZE_UNIFORM_NAME ".zw * 2 + vec2(-1, 1));\n"
+		"	vec2 temp = ((position + vec2(-0.5, 0.5)) * lss.scales[layer] + cell_position + vec2(0.5, -0.5)) * " GRID_SIZE_UNIFORM_NAME ".zw * 2 + vec2(-1, 1);\n"
 		"	gl_Position = vec4(temp.x, -temp.y, 0, 1);\n"
 		"}";
 
@@ -58,25 +64,21 @@ namespace
 		"	vec2 texcoord;\n"
 		"} gs_in[];\n"
 		"flat out int sprite;\n"
-		"layout (std430, binding = 0) buffer LayerScales"
-		"{\n"
-		"	float scales[];\n"
-		"} lss;\n"
 		"out vec2 texcoord;\n"
 		"void main()\n"
 		"{\n"
 		"	gl_Layer = gs_in[0].layer;\n"
-		"	gl_Position = vec4(gl_in[0].gl_Position.xy * lss.scales[gs_in[0].layer] + gs_in[0].offset, 0, 1);\n"
+		"	gl_Position = vec4(gl_in[0].gl_Position.xy + gs_in[0].offset * 2, 0, 1);\n"
 		"	sprite = gs_in[0].sprite;\n"
 		"	texcoord = gs_in[0].texcoord;\n"
 		"	EmitVertex();\n"
 		"	gl_Layer = gs_in[1].layer;\n"
-		"	gl_Position = vec4(gl_in[1].gl_Position.xy * lss.scales[gs_in[1].layer] + gs_in[1].offset, 0, 1);\n"
+		"	gl_Position = vec4(gl_in[1].gl_Position.xy + gs_in[1].offset * 2, 0, 1);\n"
 		"	sprite = gs_in[1].sprite;\n"
 		"	texcoord = gs_in[1].texcoord;\n"
 		"	EmitVertex();\n"
 		"	gl_Layer = gs_in[2].layer;\n"
-		"	gl_Position = vec4(gl_in[2].gl_Position.xy * lss.scales[gs_in[2].layer] + gs_in[2].offset, 0, 1);\n"
+		"	gl_Position = vec4(gl_in[2].gl_Position.xy + gs_in[2].offset * 2, 0, 1);\n"
 		"	sprite = gs_in[2].sprite;\n"
 		"	texcoord = gs_in[2].texcoord;\n"
 		"	EmitVertex();\n"
@@ -112,11 +114,12 @@ namespace
 		"{\n"
 		"	vec4 colors[];\n"
 		"} lcs;\n"
+		"uniform int " LAYER_COUNT_UNIFORM_NAME ";\n"
 		"out vec4 FragColor;\n"
 		"void main()\n"
 		"{\n"
 		"	vec3 current_color = vec3(0);\n"
-		"	for (int i = 0; i < 256; i++)\n"
+		"	for (int i = 0; i < " LAYER_COUNT_UNIFORM_NAME "; i++)\n"
 		"	{\n"
 		"		vec4 texsample = lcs.colors[i] * texture(" LAYERS_UNIFORM_NAME ", vec3(texcoord, i));\n"
 		"		current_color = mix(current_color, texsample.rgb, texsample.a);\n"
@@ -199,7 +202,7 @@ namespace glerminal
 		update_layer_colors();
 		update_layer_scales();
 
-		glViewport(0, 0, GRID_WIDTH * CELL_SIZE, GRID_HEIGHT * CELL_SIZE);
+		glViewport(0, 0, SCREEN_WIDTH, SCREEN_HEIGHT);
 		glUseProgram(m_program);
 		glBindFramebuffer(GL_FRAMEBUFFER, m_framebuffer);
 		glBindVertexArray(m_vao);
@@ -511,7 +514,7 @@ namespace glerminal
 		m_screen_size_uniform_location = glGetUniformLocation(m_program, GRID_SIZE_UNIFORM_NAME);
 
 		glUseProgram(m_program);
-		glUniform4f(m_screen_size_uniform_location, GRID_WIDTH, GRID_HEIGHT, 1.0f / GRID_WIDTH, 1.0f / GRID_HEIGHT);
+		glUniform4f(m_screen_size_uniform_location, GRID_WIDTH, GRID_AREA, 1.0f / GRID_WIDTH, 1.0f / GRID_HEIGHT);
 
 		// compile
 		const unsigned int screen_vertex_shader = glCreateShader(GL_VERTEX_SHADER);
@@ -597,13 +600,15 @@ namespace glerminal
 		glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_BASE_LEVEL, 0);
 		glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_MAX_LEVEL, 0);
 
-		glTexStorage3D(GL_TEXTURE_2D_ARRAY, 1, GL_RGBA8, GRID_WIDTH * CELL_SIZE, GRID_HEIGHT * CELL_SIZE, LAYER_COUNT);
+		glTexStorage3D(GL_TEXTURE_2D_ARRAY, 1, GL_RGBA8, SCREEN_WIDTH, SCREEN_HEIGHT, LAYER_COUNT);
 		glFramebufferTexture(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, m_framebuffer_backing_texture, 0);
 
 		glBindTextureUnit(1, m_framebuffer_backing_texture);
 
 		// setup uniforms for screen shader
 		glUseProgram(m_screen_program);
+
+		glUniform1i(glGetUniformLocation(m_screen_program, LAYER_COUNT_UNIFORM_NAME), LAYER_COUNT);
 	}
 
 	void glerminal::deinit_glfw()